Question

Given,2240 ml of ${{H}_{2}}$ at NTP will be given by reaction of:
A. 4.6 g of Na with excess of water
B. 6.5 g of Zn with 5 g of HCl
C. 6.35 g of Cu with excess of dil. HCl
D. All of the above

Answer 1

Hint: NTP means natural temperature and pressure. NTP means at a temperature of 20 $^{o}C$ and one atm pressure. Few metals react with water and acids and produce hydrogen gas as the product.
\[Metal+Acid\text{ }or\text{ }water\to salt\text{ }or\text{ }base+hydrogen\text{ }gas\]

Complete answer:
- In the question it is given that 2240 ml of hydrogen gas is produced by which option among the given options.
- Coming to the options, Option A, 4.6 g of Na with excess of water
\[2Na+2{{H}_{2}}O\to 2NaOH+{{H}_{2}}\]
- In the above chemical reaction two moles of sodium (molecular weight = 46 g) reacts with water and produces 22400ml of hydrogen at NTP.
Means 46 g of sodium (Na) gives hydrogen at N.T.P = 22400 mL
Therefore 4.6 g of Sodium (Na) gives hydrogen at N.T.P
\[\begin{align}
  & =\dfrac{22400\times 4.6}{46} \\
 & =2240ml \\
\end{align}\]
- Therefore option A is correct.
- Coming to option B, 6.5 g of Zn with 5 g of HCl.
\[Zn+2HCl\to ZnC{{l}_{2}}+{{H}_{2}}\]
- In the above chemical reaction one moles of zinc (molecular weight = 65 g) reacts with HCl and produces 22400ml of hydrogen at NTP.
Means 65 g of Zinc (Na) gives hydrogen at N.T.P = 22400 mL
Therefore 6.5 g of Zinc (Na) gives hydrogen at N.T.P
\[\begin{align}
  & =\dfrac{22400\times 6.5}{65} \\
 & =2240ml \\
\end{align}\]
- Therefore option B is correct.
- Coming to option C, 6.35 g of Cu with excess of dil. HCl.
\[Cu+2HCl\to CuC{{l}_{2}}+{{H}_{2}}\]
- In the above chemical reaction one moles of copper (molecular weight = 63.5 g) reacts with HCl and produces 22400ml of hydrogen at NTP.
Means 63.5 g of copper (Na) gives hydrogen at N.T.P = 22400 mL
Therefore 6.35 g of Copper (Na) gives hydrogen at N.T.P
\[\begin{align}
  & =\dfrac{22400\times 6.35}{63.5} \\
 & =2240ml \\
\end{align}\]
- Therefore option C is also correct.

So, the correct option is D, All of the above.

Note:
Sodium reacts with water and forms sodium hydroxide and hydrogen gas as the products. But few metals react with acids and liberate hydrogen gas and metal chlorides as the products and the metals are copper and zinc.