Answer:
The mass of 0.280 mole sample of sodium hydroxide NaOH is 11.2 grams.
Explanation:
To know the mass in grams of 0.280 moles of sample of sodium hydroxide NaOH, you must know the molar mass of the compound, that is, the mass of one mole of a substance, which can be an element or a compound.
So you know:
- Na: 23 g/mole
- O: 16 g/mole
- H: 1 g/mole
So, the molar mass of NaOH is:
NaOH= 23 g/mole + 16 g/mole+ 1 g/mole= 40 g/mole
Then the following rule of three can be applied: if in 1 mole of sodium hydroxide there are 40 grams, in 0.280 moles how much mass is there?

mass= 11.2 grams
<u><em>The mass of 0.280 mole sample of sodium hydroxide NaOH is 11.2 grams.</em></u>
The reaction is given by

Barium goes underneath beta decay to form Ceaseum
- Cs is very mellable element
- It can melt on your hand
Thank you for the free 15 points .
The head of the phospholipids molecule is attracted to water, the tail repels water
The balanced chemical reaction is:
<span>2H2O= 2H2 + O2
</span>
We are given the amount of oxygen to be produced in the reaction. The starting point for the calculations will be this amount.
50 g ( 1 mol O2 / 32 g O2 ) ( 2 mol H2O / 1 mol O2 ) ( 18.01 g H2O / 1 mol H2O) = 56.28 g of H2O is needed.
Therefore, the correct answer is the last option.