MCQ
$10\,g$ of $CaCO_3$ contains
- A$10\,moles$ of $CaCO_3$
- ✓$0.1\,g$ atom of $Ca$
- C$6\times 10^{23}$ atoms of $Ca$
- D$0.1$ of equivalent of $Ca$
$ \text { Moles of } \mathrm{CaCO}_{3} \text { in } 10 \,\mathrm{g} =\frac{10}{100} $
$=0.1\, \mathrm{mol}=0.1 \,\mathrm{g} \,\text { atom }$
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| Cations | Group reaction |
| $P \rightarrow Pb ^{2+}, Cu ^{2+}$ | $(i)$ $H _2 S$ gas in presence of dilute $HCl$ |
| $Q \rightarrow Al ^{3+}, Fe ^{3+}$ | $(ii)$ $\left( NH _4\right)_2 CO _3$ in presence of $NH _4 OH$ |
| $R \rightarrow Co ^{2+}, Ni ^{2+}$ | $(iii)$ $NH _4 OH$ in presence of $NH _4 CI$ |
| $S \rightarrow Ba ^{2+}, Ca ^{2+}$ | $(iv)$ $H _2 S$ in presence of $NH _4 OH$ |
Statement $I :$ Bohr's theory accounts for the stability and line spectrum of $Li ^{+}$ ion.
Statement $II :$ Bohr's theory was unable to explain the splitting of spectral lines in the presence of a magnetic field.
In the light of the above statements, choose the most appropriate answer from the options given below:
$A_{(g)} \longrightarrow B_{(g)} + C_{(g)}$
The initial pressure of the system before deomposition of $A$ was $P_i$. After time $'t'$ total pressure of the system increased by $x\, units$ and become $'P_t'$. The rate constant $k$ for reaction is given as