Answer:
Rubbing your hands together converts mechanical energy to thermal energy. Turning on a light switch converts mechanical energy to electrical and radiant energy.
Which are the physical properties of water
Answer:
Some physical properties of water:
It is odorless.It could appear as a white crystalline solid in solid form, a transparent gas with almost no color but a slight hint of blue in liquid form, or a colorless gas in gas form.It has a melting point of 0°C and a boiling point of 100°C.Its density (at 25°C) is about 0.99701 grams/cm³.It has a viscosity of 0.8903 centi-poise.Of course, there are many more but these are some common ones.
Propane (C3H8), a common fuel, reacts with oxygen to form carbon dioxide and water according to the equation below: C3H8 + 5O2 → 3CO2 + 4H2O If a propane heater burns 38.95 g C3H8, it consumes
Answer:
0.8833 mole of C3H8
Explanation:
Given:
Mass of C₃H₈ (Propane) = 38.95 gram
Computation:
Molar mass of C = 12.01
Molar mass of H = 1.008
Molar mass of C₃H₈ (Propane) = 3(12.01) + 8(1.008)
Molar mass of C₃H₈ (Propane) = 36.03 + 8.064
Molar mass of C₃H₈ (Propane) = 44.094
Number of mol in 38.95 gram Propane = Mass / Molar mass
Number of mol in 38.95 gram Propane = 38.95 / 44.094
Number of mol in 38.95 gram Propane = 0.88334
Answer:
Use the Periodic Table to find molar masses.
Propane (C3H8), a common fuel, reacts with oxygen to form carbon dioxide and water according to the equation below:
C3H8 + 5O2 → 3CO2 + 4H2O
If a propane heater burns 38.95 g C3H8, it consumes
38.95 mol C3H8.
0.8830 mol C3H8.
1 mol C3H8.
44.10 mol C3H8.
Part 2
How many moles of oxygen are required to produce 37.15 g CO2?
37.15 g CO2 = 1.407 mol O2
Part 3
What mass of propane is necessary to react with the amount of oxygen calculated in the previous question?
12.41 g C3H8
the overall take away of an experiment’s results is the______. A. hypothesis B. introduction C. conclusion
Answer:
conclusion
Explanation:
it can't be a hypothesis since tests are carried out to verify so it is not a theory
an introduction to an experiment only gives the basis of what we are investigating therefore nothing has been proven and the question is still unanswered
The overall takeaway of an experiment’s results is the conclusion. Hence, option C is correct.
What is a hypothesis?A hypothesis is a testable statement about the relationship between two or more variables or a proposed explanation for some observed experiment.
The overall takeaway of an experiment’s results can't be a hypothesis since tests are carried out to verify so it is not a theory
An experiment only gives an idea about the investigation therefore nothing has been proven and the question is still unanswered.
Hence, the overall takeaway of an experiment’s results is the conclusion.
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Explain how the energy of a toy car is transformed as it slides down a ramp. Give evidence that the energy of the car remains the same at all points on the ramp. (30 points)
Answer:
As the car starts to slide down the ramp, it is kinetic energy and when it's on the top of the ramp, it is potential energy. We can see that the energy is now being transferred through the car and ramp.
What happens when a chlorine atom gains an electron in its outer energy shell? A. It has an increase in the number of protons B. It becomes a negative ion C. It becomes a positive ion D. It has a decrease in the number of neutrons
Answer:
When a chlorine atom gains an electron, its outermost principal energy level achieves an octet. In this case, the ion has the same outermost shell as the original atom, but now that shell has eight electrons in it. Once again, the octet rule has been satisfied.
Explanation:
anyone knows how to do this-
Explanation:
The number of protons in the element C^12 (Carbon) is 6, number of electrons 12 and number of Neutrons is 6, same as the number of protons it contains
C^13 has 13 electrons, 6 protons and 7 Neutrons this one's neutron number is different from proton number because it's an isotope
Na^-1 has gained an electron so the number of electrons it has = 24 and the number of protons shown as 11 which means there are 23 - 11 = 12 Neutrons
O^-2 has gained two electrons and got 18 electrons in total, 8 protons and 8 neutrons
What combination of substances will give a buffered solution that has a pH of 5.05? (Assume each pair of substances is dissolved in 5.0 L of water.) (Kb for NH3 = 1.8 ´ 10–5; Kb for C5H5N = 1.7 ´ 10–9) Select one: a. 1.0 mole NH3 and 1.5 mole NH4Cl b. 1.5 mole NH3 and 1.0 mole NH4Cl c. 1.0 mole C5H5N and 1.5 mole C5H5NHCl d. 1.5 mole C5H5N and 1.0 mole C5H5NHCl e. none of these
Answer:
c. 1.0 mole C5H5N and 1.5 mole C5H5NHCl
Explanation:
We can determine pH of a buffer using H-H equation:
pH = pKa + log [A⁻] / [HA]
Where [A⁻] is concentration of conjugate base and [HA] concentration of weak acid. These concentrations can be computed as moles of each species.
We need to determine pKa of both NH₃ and C₅H₅N buffers, thus:
pKb = -log Kb
NH₃ pKb = -log 1.8x10⁻⁵ = 4.74
C₅H₅N pKb = -log 1.7x10⁻⁹ = 8.77
And pKa = 14 - pKb:
NH₃ pKa = 14 - 4.74 = 9.26
C₅H₅N pKb = 14 - 8.77 = 5.23
A buffer works only under pH's between pKa-1 and pKa + 1. As pKa NH₃ buffer is 9.23 is not possible to produce a buffer with pH 5.05 for this system.
Thus, we only will compute the buffers made with C₅H₅N:
c. 1.0 mole C5H5N (Weak base) and 1.5 mole C5H5NHCl (Conjugate acid)
pH = pKa + log [A⁻] / [HA]
pH = 5.23+ log [1.0 moles] / 1.5 moles]
pH = 5.05d. 1.5 mole C5H5N and 1.0 mole C5H5NHCl
pH = pKa + log [A⁻] / [HA]
pH = 5.23+ log [1.5 moles] / 1.0 moles]
pH = 5.41Right solution is:
c. 1.0 mole C5H5N and 1.5 mole C5H5NHClPlease help me...
Atoms of elements X, Y and Z have 16, 17 and 19 electrons, respectively. Atoms of argon have 18 electrons.
a Determine the formulae of the compounds formed by the combination of the atoms of the elements:
(i) X and Z
(ii) Y and Z
(iii) X with itself.
b In each of the cases shown in
A (i)–(iii) above, name the type of chemical bond formed.
c Give two properties you would expect to be shown by the compounds formed in an (ii) and an (iii).
Answer:
a 1) XZ2
2) YZ
3) X2
b 1) Ionic bond
2) Ionic bond
3) covalent bond
c) ionic compounds has high melting and boiling point
ionic compounds can conduct electicity in aqueous form
covalent compounds have electrons shared between the atoms
covalent compounds have lower melting point compared to ionic compound
Answer:
(i) XZ = Potassium Sulfide [K2SO4]
(ii) YZ = Potassium Chloride [KCI]
(iii) X = Sulfur [S]
b) (i) Ionic Bond. (ii) Ionic Bond. (iii) Covalent Bond.
c) (i) Ionic compounds have high melting and boiling points.
(ii) Ionic compounds can conduct electricity in a molten state or a solution as they have ions that can move and carry charge.
(iii) Covalent compounds have low melting and boiling points.
(iv) Covalent compounds can not conduct electricity as all electrons are involved in bonding so there are no free electrons or ions to carry the charge.
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3.7500 x 104 + 9.7100 x 105
Answer: [tex]1409.55[/tex]
Remove the 0's from each decimal number
[tex]3.7500 ---> 3.75\\9.7100 ---> 9.71[/tex]
Multiply
[tex]3.75*104=390\\9.71*105=1019.55[/tex]
Add
[tex]930+1019.55=1409.55[/tex]
The density of a 39 gram object with a volume of 5 cm is
Answer:
[tex]\huge\boxed{\sf D = 7.8 \ g/cm^3}[/tex]
Explanation:
Density = Mass / Volume
Where Mass = 39 g and Volume = 5 cm³
So,
[tex]\sf Density = \frac{39}{5} \\Density = 7.8 g/cm^3[/tex]
I'll GIVE BRAINLIEST: In a redox reaction, CO is changed to CO2. How many electrons must be lost or gained by C and why?
Answer:
C is gaining 2 electrons
Explanation:
O has a 2- charge so for CO to pick up another O atom would add 2 more electrons.
Answer:
C gains 2 electrons
Explanation:
In the redox reaction, CO is changed into CO2 which means there is an additional oxygen. Oxygen loses 2 of its electrons in order to neutralize. So, C must be gaining 2 electrons in order to make the bond.
how many oxygen atoms are in 7.25g of calcium nitrate
Answer:
The answer to this question is approximately equal to 1.6 ×
[tex] 1.6 \times {10}^{23} atom \: o[/tex]
how much energy has your body used, in joules, if your health device indicates that 450 calories were burned during your workout
Answer:
Total energy consumed = 1,882.8 joules
Explanation:
Given:
Calories burned = 450 calories
Find:
Total energy consumed
Computation:
1 calorie = 4.184 joules
So,
450 calories = 4.184 × 450
450 calories = 1,882.8 joules
Total energy consumed = 1,882.8 joules
calculate the pH of 500cm3 of 0.2mol/dm3 Ca(OH2), assume complete ionisation
Answer:
The pH of 500 cm³, 0.2 mol/dm³, Ca(OH₂) is ≈ 13.6
Explanation:
The given parameters are;
Concentration of the calcium hydroxide, Ca(OH₂) = 0.2 mol/dm³
Volume of the calcium hydroxide, Ca(OH₂) = 500 cm³
Given that the calcium hydroxide, Ca(OH₂), undergoes complete ionization in water, complete dissociation, we have;
Ca(OH₂) ⇄ Ca²⁺ + 2 OH⁻
Therefore, we have;
2 moles of [OH⁻] for each mole of Ca(OH₂) which gives the concentration of [OH⁻] as
[OH⁻] = 2 × 0.2 ≈ 0.4 mol/dm³
The pH is given by the formula
pH = 14 + ㏒₁₀ [OH⁻]
pH = 14 + ㏒₁₀ (0.4) = 14 - 0.3979 = 13.6021 ≈ 13.6
The pH of the 500 cm³ 0.2 mol/dm³ Ca(OH₂) ≈ 13.6.
which of the following compounds is carbon tetrafluoride
Answer: CF4 is the formula
Explanation:
Answer:
CH4
Explanation:
This answer is for APEX
calculate the weight of 3.491 into 10 to the power 19 molecules of cl2
Answer:
The mass of 3.491 × 10¹⁹ molecules of Cl₂ of Cl₂ is 4.11 × 10⁻³ grams
Explanation:
The number of particles in one mole of a substance id=s given by the Avogadro's number which is approximately 6.023 × 10²³ particles
Therefore, we have;
One mole of Cl₂ gas, which is a compound, contains 6.023 × 10²³ individual molecules of Cl₂
3.491 × 10¹⁹ molecules of Cl₂ is equivalent to (3.491 × 10¹⁹)/(6.023 × 10²³) = 5.796 × 10⁻⁵ moles of Cl₂
The mass of one mole of Cl₂ = 70.906 g/mol
The mass of 5.796 × 10⁻⁵ moles of Cl₂ = 70.906 × 5.796 × 10^(-5) = 4.11 × 10⁻³ grams
Therefore;
The mass of 3.491 × 10¹⁹ molecules of Cl₂ of Cl₂ = 4.11 × 10⁻³ grams.
Which of the following is the correct chemical formula for Ca and F? CaF Ca2F CaF2
Answer:
CaF2
Explanation:
Calcium fluoride is a solid formed by the chemical combination of Calcium (Ca) and Fluorine (F). Two molecules of fluorine (F2) and one molecule of Calcium (Ca) are needed to form the Calcium Fluoride molecule.
An ionic bond is formed between the Calcium and Fluorine atoms i.e. electrons are transferred from calcium atoms to fluorine atoms. The calcium ion is a cation with formula; Ca2+ while fluorine is an anion with formula; F-. Hence, it takes two molecules of Fluorine ion (F-) to form a relatively stable and neutral molecule with 1 molecule of Calcium ion (Ca2+).
If you are designing an experiment, how will you determine your independent or dependent variable?
Answer:
The independent variable effects the dependent variable.
Explanation:
The independent variable Is what you change whereas the dependent variable would change because of that.
for example, the indipendent variable could be how much you water a plant in ml each day, and the dependent variable would be how tall each plant grown]s with that water doseage per day.
Calculate the number of molecules present in 2.50 mol H2S?
A. 1.51 x 10^24 molecules
B. 2.50 x 10^23 molecules
C. 1.5 x 10^23 molecules
One mole of H₂S gas contains 6.022 × 10²³ H₂S molecules. Hence, 2.50 mol of H₂S contains 1.50 × 10²⁴ molecules. Thus, option A is correct.
What is Avogadro number?Any substance containing 6.022 × 10²³ number of atoms is called one mole of that substance. This number is called Avogadro number. Thus, one mole every elements contains Avogadro number of atoms.
Similarly a compound is made of molecules. One mole of a compound contains 6.022 × 10²³ number of molecules. The mass of a compound with Avogadro number of molecules is called its molar mass.
As any other compound, one mole of H₂S contains 6.022 × 10²³ molecules. Therefore, the number of molecules in 2.50 moles of H₂S is :
2.50 moles × 6.022 × 10²³ molecules/mol = 1.50 × 10²⁴molecules
Hence, the number of molecules present in 2.50 moles of H₂S is 1.50 × 10²⁴.
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Levi decides to examine the effect of fertilizer on the growth of tomato plants. He chooses four plants for his experiment and applies varying amounts of fertilizer to three of them. He does not apply fertilizer to one plant. Over a 15-day period, the plants receive fertilizer on Days 1, 4, 7, 10, and 13. Levi measures the height of all of his plants with a meter stick on days 3, 6, 9, 12, and 15. He also makes sure to hold all experimental factors constant except for the fertilizer.
Where should the independent and dependent variables of Levi's experiment be placed when graphed?
Select all that apply.
the amount of fertilizer;y-axis
plant height;x-axis
the amount of fertilizer;x-axis
plant height; y-axis
Answer:
the amount of fertilizer; x-axis
plant height; y-axis
Explanation:
The independent and dependent variables of Levi's experiment placed when graphed are the amount of fertilizer and the y-axis. Option B is correct.
What are independent and dependent variables?The independent variables are those which are not dependent on other factors for their working or cannot be influenced by any other factor and the dependent variable is just the opposite of this one.
The experiment depends on the height of the plant but the fertilizer is independent of to work of the plant and fertilizer is independent and high and depends on other factors.
Therefore, Option B is correct. independent and dependent variables of Levi's experiment placed when graphed are the amount of fertilizer and the y-axis.
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Ytu perform an electrolysis reaction using FeCl, iron (1) chloride. Which of the following will happen?
A. Chlorine will move to the positive electrode and become reduced.
B. Iron will move to the positive electrode and become oxidized.
C. Chlorine will move to the negative electrode and become oxidized.
D. Iron will move to the negative electrode and become reduced.
Answer:
The answer is "Option B"
Explanation:
when we react with FeCl, iron, and chloride to both the electrolysis. So, iron is charged positive ion, as well as passes to the negative, is cathode electrode. But there is a decrease in the cathode.
The equation can be defined as follows:
[tex]FeCl_2[/tex] [tex]\longrightarrow[/tex][tex]Fe + Cl_2[/tex]
In the above equation, when the iron chloride electrolysis solution, it will give the iron(II) and the chlorine. This process happens when the hydrogen chloride solution at a temperature of about 90 ° C.
Answer: D
Explanation: As Fe is positive charged while chlorine is negative charged.
(D) is correct. As iron moves to negative and it get reduce as negative electrode is cathode
What is conservation area write in 8 points
Answer:
The Conservation area is the pay way to the special architectural and historic interest these are special character.
Explanation:
Conservation area is the features of building and use that historical development to contribute to its special character material and style.
Conservation area is that contain process to the application management development process and local residents.Conservation is that the produce demolition of a building structure with the conservation area,contribute to the group in individually.Conservation area that are special protection in the trees to the dangerous tree and some of the fruit trees.Conservation area are often to the protected by their building, planning works, these character area of appearance.Development rights to the conservation area require to the planning and permission to the outside area.Conservation area is classified to the regulation and the restricted area to the department planning.Conservation area is a composed to the impact of materials and building and the setting of impact.The new development in the conservation area is to the process of the renewal and the managed in the conservation area.A balloon is floating around outside your window. The temperature outside is 31 ∘C , and the air pressure is 0.700 atm . Your neighbor, who released the balloon, tells you that he filled it with 4.10 moles of gas. What is the volume of gas inside this balloon? Express to THREE signficant figures.
Answer:
the volume of gas inside this balloon = 146.3 L
Explanation:
Given that:
The temperature T = 31 °C = ( 31 + 273.15 )K = 304.15 K
The air pressure P = 0.700 atm
number of moles of gas n = 4.10 moles
Gas constant = 0.0821 L atm/K/mol
The objective is to calculate the volume of the gas inside the ballon.
Using the Ideal gas equation
PV = nRT
V = nRT/P
V = (4.10×0.0821×304.15)/0.700
V = 102.3799/0.700
V = 146.257 L
V = 146.3 L
Thus, the volume of gas inside this balloon = 146.3 L
Why is graphite slippery when pressed? Select one: a. covalent bonds break b. hexagonal layers slide c. molecules of graphite slide
Answer:
hexagonal layers slide
Explanation:
The layers in graphite can slide over each other because the forces between them are weak. The delocalised electrons are free to move through the structure, so graphite can conduct electricity.This makes graphite slippery, so it is useful as a lubricant .
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tion 1/3
A white rhinoceros weighs about 1,500 pounds (lb). How many tons (T) does the rhinoceros weigh? (1 T =
A. 1.5 T
o
B. 1 T
C. 0.75 T
D. 0.5 T
Answer:
.75 Tons
Explanation:
1 Ton is equal to 2,000 pounds
An element’s most stable ion forms an ionic compound with bromine, having the formula XBr2. If the ion of element "X" has a mass number of 230 and has 86 electrons, what is the identity of the element, and how many neutrons does it have?
Answer:
88
Explanation:
The ion has a charge of 2+, therefore the number of neutrons it possess is 86+2
which equals 88
The element X having a mass number of 230 and has 86 electrons is radium and has 142 neutrons.
An atom is composed basically of electrons, protons and neutrons. In a neutral atom, the number of protons and electrons are equal. The number of neutrons is the difference between the mass number and the number of protons (atomic number).
Since we know that the ion of the element X has 86 electrons and the compound formed is XBr2, it then means that neutral X has 88 electrons.
The number of electrons in the neutral atom is the same as the number of protons or atomic number. An element can be identified by its atomic number. The element having atomic number 88 is radium.
The number of neutrons is obtained as;
Mass number - atomic number
230 - 88 = 142 neutrons
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HELPPPP Name the three states of matter. Describe the arrangement and movement of atoms in a substance for each state.
Solid, Liquid, and Gas
Solid is the state in which matter maintains a fixed volume and shape; liquid is the state in which matter adapts to the shape of its container but varies only slightly in volume; and gas is the state in which matter expands to occupy the volume and shape of its container.
The states of matter are solid, liquid, and gas. Solid is the state in which matter maintains a fixed volume and shape; liquid is the state in which matter adjusts to the shape of its container but tends to vary only mildly in volume; and gas is the state in which matter expands to occupy the volume and shape of its container.
What is matter?Matter would be any substance with mass and volume that occupies space.
Matter exists in three states: solid, liquid, and gas. The states of matter are solid, liquid, and gas.
Solid is the phase in which matter retains a fixed volume and shape.Liquid is the entity in which matter adjusts to the shape of its container but tends to vary only slightly in volume.Gas is the phase in which matter expands to occupy the volume and shape of its container.Thus, above-mentioned are the three states of matter.
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What would be the pH of an HNO3 solution if the [H+] = 3.26 x 10-6 moles/liter? 5.49 4.67 6.32
Answer:
5.49
Explanation:
pH = - log[3.26 x 10-6] =5.49
If a gas displays a solubility of 0.00290M at a partial pressure of 125 kPa, what is the proportionality constant for this gas in this solvent and at this temperature?
Answer:
The proportionality constant ( Henry’s constant) = 2.32 * 10^-5 M/kPa
Explanation:
Here in this question, we are concerned with calculating the proportionality constant for this gas.
Mathematically, we can get this from Henry law
From Henry law;
Concentration = Henry constant * partial pressure
Thus Henry constant = concentration/partial pressure
Henry constant = 0.00290 M/125 kPa = 2.32 * 10^-5 M/kPa
Which of the following has the least H+ ions in its solution?
A. Carbonic acid solution with a pH of 4.
B. Ethanoic acid solution with a pH of 6.5
C. Ammonia solution with a pH of 12.
D. Hydrochloric acid solution with a pH of 1.
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Answer:
The answer is D. Hydrochloric acid solution with a pH of 1.
Explanation:
I just took the same quiz
Hydrochloric acid solution with a pH of 1. Hence, option D is correct.
What is an acid?An acid is an electrolyte that hydrolyses in water to release hydrogen ions.
The lower the pH the greater the concentration of H+ ions. Hydrochloric acid with a pH of 1 is a strong acid and is highly ionised in solution. It has the most H+ ions.
Hence, option D is correct.
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