A solution is made by dissolving 62.42 g of ammonium sulfate in enough water to make 50.0 mL of solution. What is the molarity of this solution?
(**Use only numerical answers with 3 significant figures. The units are given
in the question.)

9.46 M

Explanation:

Molarity is a measure of the molar concentration of a solution. It can be calculated by the following formula

Molarity = number of moles/volume

Using moles = mass/molar mass

Molar Mass of Ammonium sulfate (NH₄)₂SO₄ =

{14 + 1(4)}2 + 32 + 16(4)

= {14 + 4}2 + 32 + 64

= 18(2) + 96

= 36 + 96

= 132g/mol

mole = mass/molar mass

mole = 62.42 ÷ 132

mole = 0.473mol

- Molarity = mole ÷ volume

Volume = 50.0 mL = 50/1000 = 0.05 L

Molarity = 0.473 ÷ 0.05

Molarity = 9.46 M

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g