<h3>
Answer:</h3>
2.125 g
<h3>
Explanation:</h3>
We have;
- Mass of NaBr sample is 11.97 g
- % composition by mass of Na in the sample is 22.34%
We are required to determine the mass of 9.51 g of a NaBr sample.
- Based on the law of of constant composition, a given sample of a compound will always contain the sample percentage composition of a given element.
In this case,
- A sample of 11.97 g of NaBr contains 22.34% of Na by mass
A sample of 9.51 g of NaBr will also contain 22.345 of Na by mass
% composition of an element by mass = (Mass of element ÷ mass of the compound) × 100
Mass of the element = (% composition of an element × mass of the compound) ÷ 100
Therefore;
Mass of sodium = (22.34% × 9.51 g) ÷ 100
= 2.125 g
Thus, the mass of sodium in 9.51 g of NaBr is 2.125 g
Answer:
a) 
is the mass of 1 mole of bricks.
b) 
moles of bricks have a mass equal to the mass of the Earth.
Explanation:
a) Mass of brick = 4.0 kg
1 mole = 
particles/ atoms/molecules
Mass of 
bricks :
is the mass of 1 mole of bricks.
b)
Mass of the Earth = M = 
Mass of 1 mole of brick = m=
Let the moles of brick with equal mass of the Earth be x.
moles of bricks have a mass equal to the mass of the Earth.
Molecules in a gas will have more movement than molecules in a solid. This is because the molecules in solid matter are packed very tightly together to maintain its shape, whereas with gases they are spaced much further apart and fairly free to move. Hope this helps!
Answer:
mass is a measure of the amount of matter in a sample or object. It is measured in grammes or kilogrammes
