What mass of hydrogen sulfide, H2S, will completely react with 2.00 moles of silver nitrate, AgNO3? 2AgNO3 (aq) + H2S (aq)
Ag2S (s) + 2HNO3 (aq)

17.0 g H2S (aq)
34.1 g H2S (aq)
46.3 g H2S (aq)
64.2 g H2S (aq)

34g

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

H2S + 2AgNO3 —> 2HNO3 + Ag2S

Next, we shall determine the number of mole of H2S required to react with 2 moles of AgNO3.

This is illustrated below:

From the balanced equation above,

We can see that 1 mole of H2S is required to react completely with 2 moles of AgNO3.

Finally, we shall convert 1 mole of H2S to grams. This is shown below:

Number of mole H2S = 1 mole

Molar mass of H2S = (2x1) + 32 = 34g/mol

Mass = number of mole x molar Mass

Mass of H2S = 1 x 34

Mass of H2S = 34g

Therefore, 34g of H2S is needed to react with 2 moles of AgNO3.