Answer:
c
Explanation:
There are 4 mg of lead present in 2000 g of a water sample. What is the
concentration of lead in m?
Answer: 130 ppm Pb
Explanation:
We use parts per million to express the concentrations of solutions that contain very, very small amounts, often called trace amounts, of a given solute.
More specifically, a solution's concentration in parts per millions tells you the number of parts of solute present for every
10
6
=
1
,
000
,
000
parts of solution. You can thus say that a
1 ppm
solution will contain exactly
1 g
of solute for every
10
6
g
of solution.
In your case, you know that you have
38
mg Pb
⋅
1 g
10
3
mg
=
3.8
⋅
10
−
2
.
g Pb
in exactly
300.0 g
=
3.000
⋅
10
2
.
g solution
This means that you can use this known composition as a conversion factor to scale up the mass of the solution to
10
6
g
10
6
g solution
⋅
3.8
⋅
10
−
2
.
g Pb
3.000
⋅
10
2
g solution
=
130 g Pb
Since this represents the mass of lead present in exactly
10
6
g
of solution, you can say that the solution has a concentration of
concentration
ppm
=
130 ppm Pb
−−−−−−−−−−−−−−−−−−−−−−−−−−−−
The answer is rounded to two sig figs, the number of sig figs you have for the mass of lead present in the sample.
Which types of chemical reactions are
considered opposites of one another?
Answer:
Hi
Explanation:
Decomposition reactions are really the opposite of combination reactions. In decomposition reactions, a single compound breaks down into two or more simpler substances (elements and/or compounds).
Explanation:
Decomposition chemical reactions
Decomposition reactions are really the opposite of combination reactions. In decomposition reactions, a single compound breaks down into two or more simpler substances (elements and/or compounds).
The decomposition of water into hydrogen and oxygen gases
and the decomposition of hydrogen peroxide t form oxygen gas and water
are examples of decomposition reactions.
Given the balanced reaction: 2KOH + H2SO4 → 2H20 + K2SO4
What mass of KOH is required to react completely with 2.70 grams of
H2SO4 to produce K2SO4 and water?
Molar mass of H2SO4 is 98 grams.
Molar mass of KOH is 56 grams.
O 2.36 g
O 3.09 g
4.73 g
O 1.54 g
I will give brainliest
Answer: 3.09 g
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} H_2SO_4=\frac{2.70g}{98g/mol}=0.0275moles[/tex]
The balanced chemical equation is
[tex]2KOH+H_2SO_4\rightarrow 6H_2O+K_2SO_4[/tex]
According to stoichiometry :
1 mole of [tex]H_2SO_4[/tex] require 2 moles of [tex]KOH[/tex]
Thus 0.0275 moles of [tex]H_2SO_4[/tex] will require=[tex]\frac{2}{1}\times 0.0275=0.0551moles[/tex] of [tex]KOH[/tex]
Mass of [tex]KOH=moles\times {\text {Molar mass}}=0.0551moles\times 56g/mol=3.09g[/tex]
Thus 3.09 g of KOH is required to react completely with 2.70 grams of
[tex]H_2SO_4[/tex]
Which elements are
considered "Noble Metals"?
Answer:
ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), silver (Ag).
Explanation:
The term "Noble Metals" traditionally refers to a group of metals that are resistant to corrosion and oxidation in moist or chemically aggressive environments. The elements commonly considered noble metals are Gold, Platinum, Palladium, Palladium, etc.
Gold is perhaps the most well-known noble metal. It is highly resistant to corrosion and oxidation. Platinum is another widely recognized noble metal. It is extremely resistant to corrosion and has a high melting point.
Palladium is a noble metal that exhibits excellent chemical stability and resistance to corrosion.
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The recipe for Bananas Foster requires 35g of ethanol to be added to the pan. The ethanol starts at room temperature (25°C) and is heated to its boiling point of 78°C. How many Joules of energy are transferred from the stove burner to the ethanol to create this temperature change? Your answer should have the correct number of significant figures. Show all work.
Given: The specific heat of ethanol is 2.46 J/g°C.
Answer:
To calculate the amount of heat released we have equation, use the equation Q = mc ΔT,
where
m= 35g
c= 2.46 J/g°C
ΔT=T2-T1 = 78-25= 53°C
now Q = mcΔT
Q = 35×2.46×53
Q = 4563.3 joule
Conclusion 4563.3 Joules of energy are transferred from the stove burner to the ethanol to create this temperature change!
What are three main ocean currents?
I
11122
11 / 22
=>
Which of the following hydrogen ion concentrations represents a solution with acidic
properties?
A
?
1 x 10-8 M
В.
?
1 x 10-2 M
C
1 x 10-11 M
D
1x 10-13 M
Activity Index
A
Answer:
A
Explanation: 11/22
Raul needs to ensure that when users enter an order into the tblOrders, the shipping date is at least two days after the order date on the data entry. Which option should he use?
Answer:
Input Mask
Explanation:
In this scenario, the best tool for Raul to use would be an Input Mask. When dealing with Microsoft Access or any other database tool, Input Masks are a great way of validating data inputs so that they always match the desired format. In this case, Raul would need to use input mask and apply the desired format while comparing it to the order date, therefore, making sure that it is always a minimum of 2 days after before it is accepted as a valid entry in the database.
Write the formula for Zn+2 (SO4)-2
Answer:
Zn2 + SO4 = Zn2(SO4)2
Explanation:
Which of the following statements is not true? a. Water is polar. b. Water stabilizes temperature. c. Water is essential for life. d. Water is the most abundant atom in Earth’s atmosphere.
Answer: d. Water is the most abundant atom in Earth’s atmosphere.
Explanation:
Water percentage in the atmosphere is 0.001 percent only as it not the major reservoir or source of water. The water is available in the atmosphere in the form of water vapors. These water vapors when aggregate and their concentration becomes high they fall down as rain on earth so the rain is collected in water reservoirs like oceans, rivers, lakes, ponds, aquifers, and other sources of water, which are the components of hydrosphere on earth. So, hydrosphere is most abundant in water. Moreover, water is not an atom instead it is the molecule formed by the combination of two molecules of hydrogen and one molecule of oxygen.
Mass = 22g Volume = 2cm3 What is the Density?
Answer:
11g/cm^3
Explanation:
The density of a substance can be found By
density= Mass/volume
From the question
mass = 22 g
volume = 2 cm³
22/2=11
We have the final answer as
11 g/cm³
Answer:
11g/cm^3
Explanation:
It is because the constant formula density is
Density=Mass/ Volume.
Therefore we have
Density=22g/2cm^3
Which is = 11g/cm^3
When you add an inert gas, the reaction
Answer: When an inert gas is added to the system in equilibrium at constant pressure, then the total volume will increase.
Explanation:
If you see a large “H” on the weather map, what type of weather can you expect there?
Answer:
High pressure.
Explanation:
The weather should have clear skies, if it is a Large "L" it would be could be stormy.
Hope this helps! have a great day!
Please help me ASAP I’m almost done.
Answer:
i think the answer is c
Explanation:
sorry if im wrong i am most likely wrong but ye
4 NH3 + 302
2N2 + 6H₂O
2.) a) A chemist burned 0.25 moles of ammonia gas (NH,) in the presence of excess oxygen
pps to produce 2.95 grams of nitrogen gas (N2). Calculate the theoretical yield of
nitrogen gas.
Answer:
this is hard
Explanation:
Answer:
I'm not sure but maybe 1 g ?!
What is true of an Arrhenius base?
O A. An Arrhenius base produces OH" ions.
O B. An Arrhenius base accepts OH ions.
O c. An Arrhenius base accepts H+ ions.
O D. An Arrhenius base produces H+ ions.
Answer:
produce OH-
Explanation:
How is it possible for scientists to know the composition of stars without traveling to the star?
Answer:
One of the most common methods used today to determine the composition of stars is spectroscopy.
Explanation:
Spectroscopy is the study of the interaction between matter and electromagnetic radiation as a function of the wavelength or frequency of the radiation.
PLEASE HELP ME NO LINKS
Answer: I don’t think the answer is A or C. Maybe B.
The word chemosynthesis means
the synthesis of organic compounds by bacteria or other living organisms using energy derived from reactions involving inorganic chemicals, typically in the absence of sunlight.
Explanation:
What would it mean if a forecaster claimed, “There will be east winds of 25 to 30 mph."
Answer: It would mean that there is wind originating from the east and blowing west at 25 - 30 mph
Which observation is true about the result of mixing kernel corn and oil?
A. The kernel dissolved in the oil.
B. The kernel corn floated above the oil
C. The kernel corn did not dissolve completely.
D. The kernel corn settled down at the bottom of the glass.
Answer:
A.The kernel dissolved in the oil.
Please Please Please Please Please Help Me (please answer this question completely and 1 will friend you and help you with your question.)
How do static charges interact, and how are they released?
Use the sentence starters provided to help you answer the scientific explanation.
Static charges interact by ___________________________.
Static charges are released when ___________________________.
My scientific explanation is:
Your answer should include at least 6 complete sentences to explain the claim, evidence and reasoning.
Be sure to check your grammar and spelling.
Answer:
Static electricity is a type of energy that is produced by friction.
Explanation:
Static electricity may be the result when there is an imbalance between the negative charges and the positive charges in the surroundings. They are non contact forces. They pull of push without actually touching the body. The charged particles interact by pulling or pushing the uncharged particles.
These charges are released when they come closer to some uncharged or other charged particles like the electrostatic charges. It is the charge build up in an area.
1,670,000,000 in
scientific notation pleaseeee
Answer:
1.67 × 10^9
Explanation:
When a 0.3546 g of vanadium metal is heated in air, it reacts with oxygen to achieve a
final mass of 0.6330 g. Calculate the empirical formula of this vanadium oxide
Answer:
V2O5 is the empirical formula of vanadium oxide
Explanation:
The molecular mass of Vanadium is 50.949 g/mol
Number of moles of vanadium = 0.3456 g/50.949 g/mol = 0.00696 moles
The molecular mass of Oxygen is 16.0 g/mol
Number of moles of Oxygen = (0.6330 – 0.354) g/16 g/mol = 0.0174 moles
Emperical formula
V (0.00696 moles/0.00696 moles) O (0.0174 moles /0.00696 moles)
V 1 O2.5
Multiply by two get a whole number
V2 O5
Balance the following equation
_MgF2 + _Li2CO3 -> _MgCO3 + _LiF
Answer:
1 MgF2 + 1 Li2CO3 --> 1 MgCO3 + 2 LiF
Explanation:
cells in animals and plants use the ___ that plants put in the air
Answer:
oxygen
Explanation:
plants and animals use oxygen
In the following molecules, the primary intermolecular attractive force is
Answer:
Dipole-dipole
Explanation:
The atomic number of a made-up element is 413. What would you also know about this element with the given information?
Answer:
number of protons in the atom
Explanation:
Everything else has something to do with neutrons or weight, which you cannot know from just the atomic number. The atomic number is how many protons are in an element
How many molecules is 6.11 moles of Zn?
The answer is 0.015295197308045
We assume you are converting between moles Zinc and gram. You can view more details on each measurement unit: molecular weight of Zinc or grams The molecular formula for Zinc is Zn
What does thermal energy refer to?
A. The chemical energy in reactions
B. The heat transferred between objects
C. The kinetic energy of particles within a system
D. The energy obtained from the sun
SUBMIT
Answer:
c
Explanation:
Thermal Energy has been the type of energy that refers to the kinetic energy of particles contained in a system. Hence, the correct option is (C).
What is thermal energy?
Thermal energy is the energy contained within a system as a result of its temperature. Thermodynamics, a branch of chemistry, states how heat is transmitted through multiple systems and how work is done in the process by the virtue of the first law of thermodynamics.
The thermal energy speeds the movement and collision of the particles present within the system. It is found in electric heat, geothermal, coals, etc. It is due to the kinetic energy that allows the movement of the particles.
Therefore, option C. the kinetic energy contained in the particles results in thermal energy.
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why is zinc more electropositive than iron?
Answer:
Zinc has more power although iron has a stong bond with metal
Explanation:
Brainliest answer?
Answer:
Zinc has more negative electrode reduction potential than iron. Zinc is more easily oxidized than iron, zinc has a lower reduction potential.
Explanation: