Name one trend observable in a periodic table
Answer:
Major periodic trends include: electronegativity, ionization energy, electron affinity, atomic radius, melting point, and metallic character.
Explanation:
These six are the major trends.
A sample was then prepared containing 14.00 mL of coffee and 8.00 mL of 4.80 ppm Li , and diluted to a 50.00 mL total volume. The ratio of the internal standard signal to the analyte signal in the unknown sample was found to be 0.840/1.000 (Li signal/Na signal). Determine the unknown concentration of Na in the coffee sample.
Answer:
The right answer is "[tex][Na^+]=5.57 \ ppm[/tex]".
Explanation:
The given values are:
[tex]\frac{A_s}{A_{coffee}} =\frac{0.840}{1.000}[/tex]
According to the question,
The concentration of standard will be:
= [tex]\frac{7.80}{50.00}\times 4.80[/tex]
= [tex]0.156\times 4.80[/tex]
= [tex]0.748 \ ppm[/tex]
Coffee after dilution,
⇒ [tex]\frac{A_{coffee}}{C_{coffee}} =F\times \frac{A_s}{C_s}[/tex]
or,
⇒ [tex]C_{coffee}=\frac{A_{coffee}}{A_s}\times \frac{C_s}{F}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{1.000}{0.840}\times \frac{0.748}{1.68}[/tex]
⇒ [tex]=1.191\times 1.3104[/tex]
⇒ [tex]=1.561 \ ppm[/tex]
hence,
In unknown sample, the concentration of coffee will be:
= [tex]1.561\times \frac{50}{14}[/tex]
= [tex]\frac{78.05}{14}[/tex]
= [tex]5.57 \ ppm[/tex]
1. How many grams of sodium carbonate must be weighed out in order to make 2.5 kg of a 35.0%
(w/w) solution?
Answer:
... x M x V. • Example: Prepare 800 mL of 2 M sodium chloride. ... solutions are indicated by w/v% and are defined as the grams of solute per ...
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Write the balanced half-reaction that occurs at the anode in a lead-acid (storage) battery during discharge. Phases are optional. anode half-reaction: Write the balanced half-reaction that occurs at the cathode in a lead-acid (storage) battery during discharge. Phases are optional. cathode half-reaction: Write the balanced overall cell reaction that occurs in the lead-acid (storage) battery during discharge. Phases are optional. overall cell reaction:
Answer: Anode: [tex]Pb+SO_4^{2-}\rightarrow PbSO_4+2e^-[/tex]
Cathode: [tex]PbO_2+4H^++SO_4^{2-}+2e^-\rightarrow PbSO_4+2H_2O[/tex]
Overall cell reaction : [tex]Pb+2SO_4^{2-}+PbO_2+4H^+\rightarrow 2PbSO_4+2H_2O[/tex]
Explanation:
Lead storage battery is a secondary cell used in automobiles and invertors. The anode is made up of lead and undergoes oxidation during discharging and cathode is made up of lead oxide and acts as cathode during discharging. The electrolyte used is dilute .
Lead storage battery acts as electrochemical cell while discharging.
Discharging reaction for Anode:
Discharging reaction for Cathode: [tex]PbO_2+4H^++SO_4^{2-}+2e^-\rightarrow PbSO_4+2H_2O[/tex]
Overall cell reaction : [tex]Pb+2SO_4^{2-}+PbO_2+4H^+\rightarrow 2PbSO_4+2H_2O[/tex]
A lead storage battery is an energy storage device. At the anode lead and sulfate ion reacts to produce Lead(II) sulfate and release two electrons.
What are anode and cathode?In secondary cells or the recharge-discharge cells during recharge, the positive electrode is the anode, while during discharge cathode is the positive electrode.
The anode (lead) of the cell undergoes an oxidation reaction during the discharge, whereas the lead oxide or the cathode undergoes reduction.
The discharging reaction at the anode of the cell is given as,
[tex]\rm Pb + SO_{4}^{2-} \rightarrow PbSO_{4} + 2e^{-}[/tex]
The discharging reaction at the cathode of the cell is given as,
[tex]\rm PbO_{2} + 4H^{+} + SO_{4}^{2-} + 2 e^{-} \rightarrow PbSO_{4} + 2H_{2}O[/tex]
The overall cell reaction is given as,
[tex]\rm Pb + 2SO_{4}^{2-} + PbO_{2} + 4H^{+} \rightarrow 2PbSO_{4} + 2H_{2}O[/tex]
Therefore, the gain and loss of electrons are represented at the cathode and the anode of the cell.
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A gas has a solubility of 2.45 g/L at a pressure of 0.750 atm. What pressure wold be required to produce an aqueous solution containing 6.25 g/L of this gas at constant temperature
Answer:
1.91 atm
Explanation:
Step 1: Calculate Henry's constant (k)
A gas has a solubility (C) of 2.45 g/L at a pressure (P) of 0.750 atm. These two variables are related to each other through Henry's law.
C = k × P
K = C/P
K = (2.45 g/L)/0.750 atm = 3.27 g/L.atm
Step 2: Calculate the pressure required to produce an aqueous solution containing 6.25 g/L of this gas at constant temperature.
We have C = 6.25 g/L and k = 3.27 g/L.atm. The required pressure is:
C = k × P
P = C/k
P = (6.25 g/L)/(3.27 g/L.atm) = 1.91 atm
In an effort to maintain homeostasis, the organ systems of the human body work to keep the body's internal water level constant. Which of the following statements describe how the human body responds when its internal water level drops too low?
A. The skeletal system produces more circulating blood cells that insecure the body’s water intake
B. The excretory system signals the kidneys to retain more water and produce more concentrated urine to decrease water loss.
C. The nervous system signals the muscles to constrict , holding more water in the digestive track and decreasing water loss .
D.The excretory system signals the kidneys to release more water into the bladder to increase water loss .
PLEASE HELP, DUE AT 12:00
Answer:
5.C6.DExplanation:
YONG ISA PO ETO HINDI KO PO ALAM TOH
How many grams of Ni are formed from 55.3 g of Ni2O3?
2Ni2O3(s)⟶4Ni(s)+3O2(g)
Answer:
39.2 g
Explanation:
2Ni₂O₃(s) ⟶ 4Ni(s) + 3O₂(g)First we convert 55.3 grams of Ni₂O₃ into moles of Ni₂O₃, using its molar mass:
55.3 g ÷ 165.39 g/mol = 0.334 mol Ni₂O₃Then we convert 0.334 moles of Ni₂O₃ into moles of Ni, using the stoichiometric coefficients of the balanced reaction:
0.334 mol Ni₂O₃ * [tex]\frac{4molNi}{2molNi_2O_3}[/tex] = 0.668 mol NiFinally we calculate how much do 0.668 Ni moles weigh, using the molar mass of Ni :
0.668 mol Ni * 58.69 g/mol = 39.2 gQuestion 2 (1 point)
An object's gravitational force depends primarily on the object's
a
density
mass
b
oc
momentum
Answer: An object's gravitational force depends primarily on the object's mass.
Explanation:
According to the Universal law of gravitation, every object whether is it is having large r small mass tends to exert a force on every other object, therefore this force is known as gravitational force.
Formula to calculate gravitational force is as follows.
[tex]F = \frac{G \times m_{1} \times m_{2}}{r^{2}}[/tex]
where,
F = Gravitational force
G = Gravitational constant = [tex]6.674 \times 10^{-11} m^{3}/kg s^{2}[/tex]
[tex]m_{1}[/tex] = mass of object 1
[tex]m_{2}[/tex] = mass of object 2
r = distance between the centers of the objects
Therefore, it means that gravitational force of an object primarily depends on an object's mass.
Thus, we can conclude that an object's gravitational force depends primarily on the object's mass.
what cause a mass defect?
○A. The mass of a nucleus is larger than it should be.
○B. The mass of a nucleus cannot be accurately measured.
○C. Mass is converted to the energy binding a nucleus together.
○D. Mass is lost when a particle is released in a reaction.
Answer: Mass is converted to the energy binding a nucleus together.
Explanation: a p e x
Mass is converted to the energy binding a nucleus together cause a mass defect.Hence , Option (C) is correct.
What is Mass defect ?
The actual atomic mass is less than the predicted mass calculated by adding the masses of nucleons.
This additional mass is accounted for by binding energy that is released when a nucleus is formed.
When a nucleus is formed, some of the mass is converted to energy and this results in the mass defect.
Therefore, Mass is converted to the energy binding a nucleus together cause a mass defect. Hence , Option (C) is correct.
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The force that contributed to the formation of planets, determines the motion of bodies in the solar system, and pulls objects to the center of Earth is called
.
The principle that states that an object at rest will stay at rest and that an object in motion will stay in motion is the law of
Answer:
Gravity and Inertia
Explanation:
Just did it on edg 2021 :)
Which
gas is exchanged in the air sac of
longs? -
oxygen and nitrogen
oxygen and carbondioxide
O nitrogen and coarbondioxide
oxygen and hydrogen
O
Other:
Answer:
oxygen and carbon dioxide.
hope this helps you
Which of the following is NOT an indication that a chemical reaction has taken place?
Answer:
WHERE ARE THE CHOICES?
PLEASE MAKE SURE THAT YOUR QUESTION IS RIGHT BEFORE POSTING IT シ︎
Change of state of matter is not an indication that a chemical change has taken place.
What is matter?Matter is a substance which is made up of various types of particles which occupy space and have inertia . All living things and objects are made up of various types of particles that occupy space and have inertia .
Depending on temperature and other factors matter is able to exist in different phases. Most common of which are solid, liquid and gas. Matter can exist in more than one state depending on the temperature and pressure .
State of matter can be changed by heating or cooling and even by changing the applied pressure.When a state changes matter does not break rather its state changes though its chemical composition remains same.
Physical characteristics of matter are shape, color, size and temperature. Every matter is made up of elements which cannot be broken down further by ordinary chemical reactions.
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to the nearest gram, what is the mass of of one spoonfull of sugar? g
Answer:
the mass of one spoonful of sugar to nearest gram is 10g
Why would you want to slow down a chemical reaction?
Answer:
We often want to decrease the rates of certain reactions rather than speeding them up. For example, to prolong the shelf lives of certain foods, the chemical reactions by which they spoil must be slowed down.
156 grams of calcium fluoride, CaF2, is dissolved in 2000 mL of solution. Determine the molarity (M).
Answer:
1 M
Explanation:
We'll begin by calculating the number of mole of in 156 g of CaF₂. This can be obtained as follow:
Mass of CaF₂ = 156 g
Molar mass of CaF₂ = 40 + (19×2)
= 40 + 38
= 78 g/mol
Mole of CaF₂ =?
Mole = mass /molar mass
Mole of CaF₂ = 156 / 78
Mole of CaF₂ = 2 moles
Next, we shall convert 2000 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
2000 mL = 2000 mL × 1 L / 1000 mL
2000 mL = 2 L
Finally, we shall determine the molarity of the solution. This can be obtained as follow:
Mole of CaF₂ = 2 moles
Volume = 2 L
Molarity =?
Molarity = mole / Volume
Molarity = 2 / 2
Molarity = 1 M
Thus, the molarity of the solution is 1 M
When ammonium nitrate dissolves in water, the solution becomes cold.
NH4NO3(s) <-> NH4+(aq) + NO3-(aq)
The reaction is thermodynamically favorable. The signs of ΔG and ΔS for the reaction are which of the following?
A.
B.
C.
D.
B.
Delta G is negative and Delta S is positive.
The main biochemical components of living things are ___
Answer:
Amines ketones aldehydes and aromatic
Explanation:
my opinion but thats my answer
which molecule is butene
Answer:
Option C is the answer
Butene, also called Butylene, 4 isomeric compound belonging to the series of olefinic hydrocarbons. The chemical formula is C4H8, option c is correct.
What are the 4 isomers of butene?Butene, also called Butylene, four isomeric Combinations belong to the series of olefinic hydrocarbons. The chemical formula is C4H8.
The isomeric forms are 1-butene, cis-2-butene, trans-2-butene, and isobutylene.
Thus, option "C" is correct. the chemical formula is C4H8.
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Which of the following are reasons the ocean marine biomes are a challenging place for organisms to live? Choose all that apply.
Question 13 options:
some areas are extremely dark and deep
high waves can be rough and powerful
all of the organisms have to live without sunlight
organisms have to be able to live in extremely salty conditions
In an ecosystem, the reason that ocean marine biomes are a challenging place for organisms to live because they have to be able to live in extremely salty conditions.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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Carbon-14 has a half-life of 5730 years. How much of a 144 g sample of carbon-14 will remain after 100,000 years?
Answer:
0.001 g
Explanation:
From the question given above, the following data were obtained:
Half-life (t½) = 5730 years
Original amount (N₀) = 144 g
Time (t) = 100,000 years
Amount remaining (N) =?
Next, we shall determine the number of half-lives that has elapsed. This can be obtained as follow:
Half-life (t½) = 5730 years
Time (t) = 100,000 years
Number of half-lives (n) =?
n = t / t½
n = 100,000 / 5730
n ≈ 17
Finally, we shall determine the amount remaining. This can be obtained as follow:
Original amount (N₀) = 144 g
Number of half-lives (n) = 17
Amount remaining (N) =?
N = 1/2ⁿ × N₀
N = 1/2¹⁷ × 144
N = 1/131072 × 144
N = 0.000007 × 144
N ≈ 0.001 g
Thus, the amount remaining after 100000 years is 0.001 g
Ito ang web browser na kapalit ng Internet Explorer! plsssss help naman ako epp po ito hindi ko po alam
Answer:
p o e t i c o
Explanation:
no lo entenderias
mplete the following Charles' Law calculations. If the current temperature is 25 degrees C and you have a 2L balloon, identify the new volume of the balloon if you increase the temperature to 30 degrees C. Remember to change Celsius to Kelvin: K= C + 273.
Answer:
New volume = 2.03 L
Explanation:
Given that
Initial temperature, T₁ = 25°C = 298 K
Initial volume, V₁ = 2L
Final temperature, T₂ = 30°C = 303 K
We need to find the final volume. The mathematical form of Charle's law is given by :
[tex]\dfrac{V_1}{V_2}=\dfrac{T_1}{T_2}\\\\V_2=\dfrac{V_1T_2}{T_1}[/tex]
Put all the values,
[tex]V_2=\dfrac{2\times 303}{298}\\\\V_2=2.03\ L[/tex]
so, the new volume is equal to 2.03 L.
Do frogs start their life cycle on land or water?
The answer is water because they lay eggs in water
the correct order of increasing ionisation energy of Na,Al,Si and Mg elements is?
Removal of an electron from stable, fully filled orbital requires more energy than removal of electron from partially filled orbital. Thus, ionisation enthalpy for Mg is greater than ionisation enthalpy for Al. So, the correct order of first ionization enthalpies is: Na<Mg>Al<Si.
what is chemical name of ghee
Answer. Chemical formula of ghee: (C17H33 Coo)3 C3H5 • Chemical Reaction: (C17H31Coo)3 C3H5 + 3H2 (C17H33 Coo)3 C3H5
what mix of chemicles gives fireworks thier color: explain for each color
Answer:
Metal salts commonly used in firework displays include: strontium carbonate (red fireworks), calcium chloride (orange fireworks), sodium nitrate (yellow fireworks), barium chloride (green fireworks) and copper chloride (blue fireworks).
Explanation:
Answer:
Metal salts commonly used in firework displays include: strontium carbonate (red fireworks), calcium chloride (orange fireworks), sodium nitrate (yellow fireworks), barium chloride (green fireworks) and copper chloride (blue fireworks).
The colors are produced by heating metal salts, such as calcium chloride or sodium nitrate, that emit characteristic colors. ... Barium – Barium is used to create green colors in fireworks, and it can also help stabilize other volatile elements. Calcium – Calcium is used to deepen firework colors
At what pressure would a 5.32 mol Cl2 sample occupy 5.08 L at 181.59 K? please help!!
Answer: At a pressure of 15.613 atm a 5.32 mol [tex]Cl_{2}[/tex] sample occupy 5.08 L at 181.59 K.
Explanation:
Given: Moles = 5.32 mol
Volume = 5.08 L
Temperature = 181.59 K
Formula used to calculate the pressure is as follows.
PV = nRT
where,
P = pressure
V = volume
n = no. of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
[tex]PV = nRT\\P \times 5.08 L = 5.32 mol \times 0.0821 L atm/mol K \times 181.59 K\\P = \frac{5.32 mol \times 0.0821 L atm/mol K \times 181.59 K}{5.08 L}\\= 15.613 atm[/tex]
Thus, we can conclude that at a pressure of 15.613 atm a 5.32 mol [tex]Cl_{2}[/tex] sample occupy 5.08 L at 181.59 K.
g A chemical equilibrium exists when: A chemical equilibrium exists when: there are equal amounts of reactants and products. the rate at which reactants form products is the same as the rate at which products form reactants. the sum of reactant and product concentrations equals one mole. reactants are completely changed to products. the rate at which reactants form products becomes zero.
Answer:
the rate at which reactants form products is the same as the rate at which products form reactants
Explanation:
There is still a reaction happening just that the second one happens the opposite happens and keeps it at net 0
Calculate the volume of 0.250 M H2SO4 that contains 0.00255 mol H2SO4.
Answer:
0.0102 L or 10.2 mL
Explanation:
From the question given above, the following data were obtained:
Molarity = 0.250 M
Mole = 0.00255 mole
Volume =?
Molarity is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole / Volume
With the above formula, we can obtain the volume as follow:
Molarity = 0.250 M
Mole = 0.00255 mole
Volume =?
Molarity = mole / Volume
0.250 = 0.00255 / volume
Cross multiply
0.250 × volume = 0.00255
Divide both side by 0.250
Volume = 0.00255 / 0.250
Volume = 0.0102 L
Covert 0.0102 L to mL.
1 L = 1000 mL
Therefore,
0.0102 L = 0.0102 L × 1000 / 1 L
0.0102 L = 10.2 mL
Thus, the volume is 0.0102 L or 10.2 mL