At constant temperature and pressure, if 0.4 mole of a gas. A occupies 220 ml, and x mole of B gas occupies 120 ml. what is the number of moles of gas B?

0.218mol

Explanation:

Using Avogadro's law equation;

Va/na = Vb/nb

Where;

Va = volume of gas A

Vb = volume of gas B

na = number of moles of gas A

nb = number of moles of gas B

According to the information in this question,

na = 0.4mol

nb = x mol

Va = 220ml

Vb = 120ml

Using Va/na = Vb/nb

220/0.4 = 120/x

Cross multiply

0.4 × 120 = 220 × x

48 = 220x

x = 48/220

x = 0.218mol

nacl is added to the aqueous of what? ? in order to get a proper answer you have to specify the exact composition of the aqueous solution.