If 25.0 grams of Sb2S3 reacts with an excess of hydrochloric acid, how many grams of H2S are formed? What volume does the H2S formed occupy under conditions of STP?

a) 7.57 g

b) 4.97 L

Explanation:

To calculate the moles :

As is the excess reagent, is the limiting reagent and it limits the formation of product.

According to stoichiometry :

1 mole of form = 3 moles of

Thus 0.074 moles of will form =  of

Mass of

According to ideal gas equation:

P = pressure of gas = 1 atm (at STP)

V = Volume of gas = ?

n = number of moles = 0.222

R = gas constant =

T =temperature =

Thus the volume occupied by is 4.97 L

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance