Question

If 30mL H2 and 20mL of O2 react to form water, what is left at the end of the reaction? 

Solution

Correct option is

mL O2

 

2 H2  + O2 → 2 H2O

2 mL    1 mL

2 mL of H2 react with 1 mol of O2. Hence, 30 mL of H2 will react with 15 mL of O2.

SIMILAR QUESTIONS

Q1

Number of atom of oxygen present in 10.6 g Na2CO3 will be 

Q2

A sample of phosphorous trichloride (PCl3) contains 1.4 moles of the substance. How many atoms are there is the sample?   

Q3

A gas mixture contains 50% helium and 50% methane by volume. What is the percent by weight of methane in the mixture?

Q4

116 mg of a compound on vaporisation in a victor Meyer’s apparatus displace 44.8 mL of air measured at STP. The molecular weight of the compound is  

Q5

100 g CaCO3 is treated with 1 litre of 1 N HCl. What would be the weight of CO2 liberated after the completion of the reaction? 

Q6

If we consider that , in place of , mass of carbon atom is taken to be relative atomic mass unit, the mass of one mole of a substance will

Q7

For the formation of 3.65 g of hydrogen chloride gas, what volumes of hydrogen gas and chlorine gas are required at N.T.P. conditions? 

Q8

An alkaloid contains 17.28% of nitrogen and its molecular mass is 162. The number of nitrogen atoms present in one molecule of the alkaloid is

Q9

How many moles of magnesium phosphate, Mg3(PO4)2 will contain 0.25 mole of oxygen atoms?

Q10

The decomposition of a certain mass CaCO3 gave 11.2 dm3 of CO2 gas at STP. The mass of KOH required to completely neutralize the gas is