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# Calulation no of moles and deducing the amount watch

1. HI there
I need help with two questions
question one
Assuming room temperature and pressure calculate the amount in mol of hydrogen gas produced. The mass of hydrogen gas is 0.15g and the volume is 101 cm^3
my teacher said that temp should be in kelvin, pressure should be in Pa and volume should be in m^3

Question 2 (continues from question 1)
Using the equation below deduce the amount in mol of magnesium that was reacted
Mg(s) + H2SO4(aq) --> MgSO4(aq) + H2(g)

it would be great if someone can help me out on this
i tried using the formula PV=nRT but i am getting a really small value for both answers and its apparently wrong
thank you
2. Do you know how to do the relevant conversions, e.g. kPa to Pa, cm^3 to dm^3 and degrees to Kelvin?
Also, remember to use the equation, moles = mass/mr where applicable.
3. (Original post by SANTR)
Do you know how to do the relevant conversions, e.g. kPa to Pa, cm^3 to dm^3 and degrees to Kelvin?
Also, remember to use the equation, moles = mass/mr where applicable.
i know how to convert these
can i use mass/mr in here
so 0.15/24
edit:
can i alsow use n= concetration times volume/1000
4. (Original post by jalp_14)
HI there
I need help with two questions
question one
Assuming room temperature and pressure calculate the amount in mol of hydrogen gas produced. The mass of hydrogen gas is 0.15g and the volume is 101 cm^3
my teacher said that temp should be in kelvin, pressure should be in Pa and volume should be in m^3

Question 2 (continues from question 1)
Using the equation below deduce the amount in mol of magnesium that was reacted
Mg(s) + H2SO4(aq) --> MgSO4(aq) + H2(g)

it would be great if someone can help me out on this
i tried using the formula PV=nRT but i am getting a really small value for both answers and its apparently wrong
thank you
For the amount in mol of hydrogen, am I missing something or would you just use n = m/mr. This would me 0.15/1, so there's 0.15 moles of hydrogen?
5. (Original post by Wright98)
For the amount in mol of hydrogen, am I missing something or would you just use n = m/mr. This would me 0.15/1, so there's 0.15 moles of hydrogen?
Oh wait I forgot hydrogen is diatomic, so 0.15/2. = 0.075 moles of hydrogen?

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