Question

What quantity of copper oxide will react with 2.80 L of hydrogen at NTP?
A. 79.5 g
B. 2 g
C. 9.9 g
D. 22.4 g

Answer 1

As we know that temperature and pressure vary at different places therefore a standard reference is needed for comparing the testing and the documentation of chemical processes and physical processes. For this NTP and STP terms are used to define their conditions.

Complete answer:
NTP terms generally refers to normal temperature and pressure. It is generally defined by NIST abbreviation of National Institute of Standards and technology. For NTP the normal temperature is $20{}^\circ C$or 293.15 K or $68{}^\circ F$and normal pressure is 1 atm or 101.325 kpa or 760 mm of Hg.
Quantity of copper oxide will react with 2.80 L of hydrogen at NTP can be calculated as:
The equation of copper oxide with hydrogen can be represented by:
$CuO+{{H}_{2}}\to Cu+{{H}_{2}}O$
1 mol of $CuO$ is equivalent to 79.5 g and 1 mol of ${{H}_{2}}$is equivalent to 22.4 litres at NTP.
Hence we can consider that
22.4 litre of hydrogen at NTP reduce $CuO$= 79.5 g
1 litre of hydrogen at NTP reduce $CuO$= $\dfrac{79.5}{22.4}$g
Therefore 2.80 litre of hydrogen at NTP reduce $CuO$is given by:
$\dfrac{79.5}{22.4}\times 2.80=9.95g$

Hence we can say that option C is the correct answer.

Note:
NTP conditions are widely used as compared to STP conditions as these conditions are more realistic and convenient in nature or we can say these conditions are easy to approach as compared to STP one where STP refers to Standard temperature and pressure.