As the question tells you, you need to use the formula

% mass= mass of solute/ mass of solution x 100

mass solute= 30.0 g
mass of solution= 30.0 + 270.0= 300.0 g

% mass= 30.0/ 300.0 x 100= 10%

answer is B

4 0

3 years ago

Which sample contains the largest number of oxygen atoms? Select one: a. 8.0 g of carbon dioxide b. 8.0 g of potassium chlorate

adell [148]

The sample with the largest number of oxygen atoms will be calcium perchlorate.

<h3>Number of atoms in a compound</h3>

Since we are not looking at the number of moles, the mass of the compounds has no bearing on the number of atoms of oxygen.

The chemical formula for carbon dioxide is $CO_2$ . Thus, it has 2 atoms of oxygen.
The chemical formula for potassium chlorate is $KClO_3$ . Thus, it has 3 oxygen atoms.
The chemical formula for calcium perchlorate is $Ca(ClO_4)_2$ . Thus, it has 8 atoms of oxygen.
The chemical formula for sodium hydroxide is NaOH. Thus, it has 1 atom of oxygen.

Therefore, the compound with the largest number of oxygen atoms is calcium perchlorate.

More on the number of atoms in compounds can be found here: brainly.com/question/1686912

#SPJ1

5 0

2 years ago