`CO(g)+H_(2)(g)overset(Cu)toX`
`CO(g)+H_(2)(g)overset(Cu//ZnO-Cr_(2)O_(3))toY`
`CO(g)+H_(2)(g)overset(Ni)toZ`
X,Y and Z respectively are

Options

A. `CH_(3) OH, HCHO, CH_(4)`
B. `HCHO, CH_(3)OH, CH_(4)`
C. `CH_(4), CH_(3)OH,k CH_(4)`
D. `CHOH, CH_(4),CH_(3)OH`

Explanation

To solve the question, we need to identify the products (X, Y, and Z) formed from the reactions of carbon monoxide (CO) and hydrogen gas (H2) in the presence of different catalysts.

### Step-by-step Solution:

1. **Identify the reaction with Copper (Cu):**
- The reaction is:
\[ CO(g) + H_2(g) \overset{Cu}{\rightarrow} X \]
- In the presence of copper, CO reacts with H2 to form formaldehyde (HCHO).
- Therefore, \( X = HCHO \).

2. **Identify the reaction with Copper, Zinc Oxide, and Chromium Oxide (Cu/ZnO-Cr2O3):**
- The reaction is:
\[ CO(g) + H_2(g) \overset{Cu/ZnO-Cr_2O_3}{\rightarrow} Y \]
- In this case, the presence of Cu with ZnO and Cr2O3 facilitates the conversion of CO and H2 to methanol (CH3OH).
- Therefore, \( Y = CH_3OH \).

3. **Identify the reaction with Nickel (Ni):**
- The reaction is:
\[ CO(g) + H_2(g) \overset{Ni}{\rightarrow} Z \]
- In the presence of nickel, CO reacts with H2 to produce methane (CH4).
- Therefore, \( Z = CH_4 \).

### Summary of Products:
- \( X = HCHO \) (Formaldehyde)
- \( Y = CH_3OH \) (Methanol)
- \( Z = CH_4 \) (Methane)

### Final Answer:
The products X, Y, and Z respectively are:
- X = HCHO
- Y = CH3OH
- Z = CH4