A student investigated the diffusion of ammonia gas, NH3, and hydrogen chloride gas, HCl. The damp red litmus paper for NH3 changed colour after 30 seconds. How long does it take for the damp blue litmus paper to change colour for HCl?

43.96secs

Explanation:

M1 = molar mass of NH3 = 14 + (3x1) = 14 + 3 = 17g/mol

t1 = time for NH3 to diffuse = 30secs

M2 = molar mass of HCl = 1 + 35.5 = 36.5g/mol

t2 = time for HCl to diffuse =?

From Graham's law of diffusion:

t2/t1 = √(M2/M1)

t2/30 = √(36.5/17)

t2/30 = 1.465

Cross multiply

t2 = 30 x 1.465

t2 = 43.96secs

Therefore it will take 43.96secs for the damp blue litmus paper to change colour for HCl.

1.consider the following balanced equation and answer parts a through. show calculations for each part.  

3 ag(s) + 4 hno3(aq) → 3 agno3(aq) + no(g) + 2 h2o(l)  

a. calculate the number of moles of agno3 produced by the reaction of 3 moles of ag with excess hno3. if the number to the left of the compound represents the number of moles of the compound which are present, then 3 moles of ag react with 4 moles hno3 to produce 3 moles agno3 (aq).

so the answer to a would be 3 moles.

b. calculate the number of moles of agno3 produced by the reaction of 108 grams of ag with excess hno3.  

i'm not sure how to plug in the grams of silver into an equation using moles to find how many moles are produced.

c. calculate the number of grams of agno3 produced by the reaction of 108 grams of ag with excess hno3  

d. calculate the number of moles of no produced as a byproduct of the reaction of 108 grams of ag with excess hno3.  

e. calculate the number of grams of no produced as a byproduct starting with 108 grams of ag and excess hno3.  

explanation: