Some Basic Concepts of Chemistry · Chemistry · NEET
MCQ (Single Correct Answer)
Among the following, choose the ones with equal number of atoms.
A. 212 g of $\mathrm{Na}_2 \mathrm{CO}_3(\mathrm{~s})$ [molar mass $=106 \mathrm{~g}$ ]
B. 248 g of $\mathrm{Na}_2 \mathrm{O}(\mathrm{s})$ [molar mass $=62 \mathrm{~g}$ ]
C. 240 g of $\mathrm{NaOH}(\mathrm{s})$ [molar mass $=40 \mathrm{~g}$ ]
D. 12 g of $\mathrm{H}_2(\mathrm{~g})$ [molar mass $=2 \mathrm{~g}$ ]
E. 220 g of $\mathrm{CO}_2(\mathrm{~g})$ [molar mass $=44 \mathrm{~g}$ ]
Choose the correct answer from the options given below:
Dalton's Atomic theory could not explain which of the following?
The amount of glucose required to prepare $$250 \mathrm{~mL}$$ of $$\frac{\mathrm{M}}{20}$$ aqueous solution is :
(Molar mass of glucose : $$180 \mathrm{~g} \mathrm{~mol}^{-1}$$)
$$1.0 \mathrm{~g}$$ of $$\mathrm{H}_2$$ has same number of molecules as in:
On complete combustion, 0.3 g of an organic compound gave 0.2 g of CO$$_2$$ and 0.1 g of H$$_2$$O. The percentage composition of carbon and hydrogen in the compound, respectively is:
1 gram of sodium hydroxide was treated with $$25 \mathrm{~mL}$$ of $$0.75 \mathrm{~M} \mathrm{~HCl}$$ solution, the mass of sodium hydroxide left unreacted is equal to
The highest number of helium atoms is in
A compound X contains $$32 \%$$ of A, $$20 \%$$ of B and remaining percentage of C. Then, the empirical formula of $$\mathrm{X}$$ is :
(Given atomic masses of A=64 ; B=40 ; C=32 u)
The density of 1 M solution of a compound 'X' is 1.25 g mL$$^{-1}$$. The correct option for the molality of solution is (Molar mass of compound X = 85 g):
The right option for the mass of $$\mathrm{CO}_{2}$$ produced by heating $$20 \mathrm{~g}$$ of $$20 \%$$ pure limestone is
(Atomic mass of $$\mathrm{Ca}=40$$ )
$$\left[\mathrm{CaCO}_{3} \stackrel{1200 \mathrm{~K}}{\longrightarrow} \mathrm{CaO}+\mathrm{CO}_{2}\right]$$
The density of the solution is 2.15 g mL$$-$$1, then mass of 2.5 mL solution in correct significant figures is :
What fraction of Fe exists as Fe(III) in Fe0.96O ?
(Consider Fe0.96O to be made up of Fe(II) and Fe(III) only)
In one molal solution that contains 0.5 mole of a solute, there is
What mass of 95% pure CaCO3 will be required to neutralise 50 mL of 0.5 M HCl solution according to the following reaction?
CaCO3(s) + 2HCl(aq) $$\to$$ CaCl2(aq) + Co2(g) + 2H2O(l)
[Calculate upto second place of decimal point]
200X : 90% 199X : 8.0% 202X : 2.0%
The weighted average atomic mass of the naturally occuring element X is closest to