Question

10 gram of hydrogen is burnt in the presence of excess of oxygen the mass of water formed is​

Answer 1

$\textsf{\Large{\underline {Stoichiometry}}}$ :

For the solution, first of all we have to form the equation.

$\mathsf{2H_2\:+\:O_2{\rightarrow{2H_2O}}}$

Mass of $\mathsf{2H_2\:=\:4\:g}$

Mass of $\mathsf{2H_{2}O\:=\:36\:g}$ [ 2*18 g = 36 g ]

By using Unitary method,

4 g of Hydrogen produces 36 g of $\mathsf{{H}_{2}O}$.

1 g of Hydrogen will produce $\mathsf{\dfrac{36}{4}\:g\:of\:{H}_{2}O}$.

10 g of Hydrogen will produce $\mathsf{\dfrac{36*10}{4}\:g\:of\:{H}_{2}O}$.

10 g of Hydrogen will produce $\mathsf{90\:g\:of\:{H}_{2}O}$.

$\boxed{\mathsf{Mass\:of\:water\:formed\:=\:90\:g}}$

➡️ Option ( a ). 90 is correct.