% composition of ethanol = 34.51%
% composition of water = 65.49%
<h3>What is density?</h3>
A material's density is defined as its mass per unit volume.
Given data:
The density of ethanol = 0.7890 g/mL
The density of water = 0.9982 g/mL
The density of mixture = 0.926 g/mL
Let the % composition of ethanol = x
Let the % composition of water = 100-x
Now density of the mixture



%
Hence,
% composition of ethanol = 34.51%
% composition of water = 65.49%
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The average mass of an atom is calculated with the formula:
average mass = abundance of isotope (1) × mass of isotope (1) + abundance of isotope (2) × mass of isotope (2) + ... an so on
For the boron we have two isotopes, so the formula will become:
average mass of boron = abundance of isotope (1) × mass of isotope (1) + abundance of isotope (2) × mass of isotope (2)
We plug in the values:
10.81 = 0.1980 × 10.012938 + 0.8020 × mass of isotope (2)
10.81 = 1.98 + 0.8020 × mass of isotope (2)
10.81 - 1.98 = 0.8020 × mass of isotope (2)
8.83 = 0.8020 × mass of isotope (2)
mass of isotope (2) = 8.83 / 0.8020
mass of isotope (2) = 11.009975
mass of isotope (1) = 10.012938 (given by the question)
Answer:- 0.273 kg
Solution:- A double replacement reaction takes place. The balanced equation is:

We have 0.29 L of 22% m/v aluminum nitrate solution. m/s stands for mass by volume. 22% m/v aluminium nitrate solution means 22 g of it are present in 100 mL solution. With this information, we can calculate the grams of aluminum nitrate present in 0.29 L.

= 63.8 g aluminum nitrate
From balanced equation, there is 1:3 mol ratio between aluminum nitrate and sodium chlorate. We will convert grams of aluminum nitrate to moles and then on multiplying it by mol ratio we get the moles of sodium chlorate that could further be converted to grams.
We need molar masses for the calculations, Molar mass of sodium chlorate is 106.44 gram per mole and molar mass of aluminum nitrate is 212.99 gram per mole.

= 
sodium chlorate solution is 35% m/m. This means 35 g of sodium chlorate are present in 100 g solution. From here, we can calculate the mass of the solution that will contain 95.7 g of sodium chlorate and then the grams are converted to kg.

= 0.273 kg
So, 0.273 kg of 35% m/m sodium chlorate solution are required.
So, what's your question..?. You just gave options..
Pb(NO₃)₂ + (NH₄)₂CO₃ → PbCO₃ + 2 NH₄NO₃
Explanation:
Reaction of lead (II) nitrate with ammonium carbonate will produce lead (II) carbonate and ammonium nitrate.
The balanced chemical equation is:
Pb(NO₃)₂ + (NH₄)₂CO₃ → PbCO₃ + 2 NH₄NO₃
To balance the chemical equation the number of atoms of each element
entering the reaction have to be equal to the number of atoms of each
element leaving the reaction, in order to conserve the mass.
Learn more about:
balancing chemical reactions
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