Some basic concepts of chemistry practice · Mixed difficulty

The number of significant figures for the three numbers 161 cm, 0.161 cm, 0.0161 cm are

Which contains greatest number of oxygen atoms?

From the equation, $3{\mathrm{C}_2}{\mathrm{H}_2} \to {\mathrm{C}_6}{\mathrm{H}_6},$ find the volume of acetylene (NTP) for the manufacture of 3 mole of benzene:

The numerical value of $\frac{\mathrm{N}}{n}$ (where, Nis the number of molecules in a given sample of gas and n is the number of moles of the gas) is

The weights of two elements which combine with one another are in the ratio of their:

Which of the following samples contain the least number of atoms

Maximum no. of atoms are present in

Which among the following has maximum number of atoms among the following?

The apparatus in which standard solution is prepared is known as :

How much time (in hours) would it take to distribute one Avogadro number of wheat grains if $10^{20}$ grains are distributed each second ?

Which one of the following set of units represents the smallest and largest amount of energy respectively?

The equivalent weight of $\mathrm{Zn}{\left( {\mathrm{OH}} \right)_2}$ in the following reaction is equal to its,
$\mathrm{Zn}{\left( {\mathrm{OH}} \right)_2} + \mathrm{HN}{\mathrm{O}_3} \to \mathrm{Zn}\left( {\mathrm{OH}} \right)\left( {\mathrm{N}{\mathrm{O}_3}} \right) + {\mathrm{H}_2}\mathrm{O}$:

Difference in density is the basis of

Which is correct for $\mathrm{N}{\mathrm{a}_2}\mathrm{HP}{\mathrm{O}_3}$?

Which statement is correct?

Consider the following statements.
(i) Atoms of $H, \, O, \, N$ and $C$ have identical properties but different mass.
(ii) Matter is divisible into atoms which are further indivisible.
(iii) The ratio of $N: H$ in $NH_3$ is 1 : 3 and $N : O$ in nitric oxide is 2 : 1.
(iv) Dalton’s atomic theory support law of conservation of mass.
Which of the following pairs of statements is true according to Dalton’s atomic theory ?

0.75 moles of a solid ${A_4}$ and 2 moles of ${O_2}(g)$ are heated in a sealed vessel, completely using up the reactants and produces only one compound. It is found that when the temperature is used to initial temperature, the contents of the vessel exhibit a pressure equal to $\frac{1}{2}$ of the original pressure. The formula of the product will be

510 mg of a liquid on vaporization in Victor meyer’s apparatus displaces $\mathrm{67}\mathrm{.2}\;\mathrm{c}{\mathrm{m}^3}$ of air at (STP). The molecular weight of the liquid is:

The number of atoms in 0.1 mol of a triatomic gas is

In the reaction $3Mg + {N_2} \to M{g_3}{N_2}$

Choose the correct statements.

(A) Weight of a substance is the amount of matter present in it.

(B) Mass is the force exerted by gravity on an object.

(C) Volume is the amount of space occupied by a substance.

(D) Temperatures below $0^\circ C$ are possible in Celsius scale, but in Kelvin scale negative
temperature is not possible.

(E) Precision refers to the closeness of various measurements for the same quantity.

In the reaction, $\mathrm{VO} + \mathrm{F}{\mathrm{e}_2}{\mathrm{O}_3} \to \mathrm{FeO} + {\mathrm{V}_2}{\mathrm{O}_5}\mathrm{.}$. The eq.wt. of ${\mathrm{V}_2}{\mathrm{O}_5}$ is equal to its :

If ${\mathrm{H}_2}\mathrm{S}{\mathrm{O}_4}$ ionises as ${\mathrm{H}_2}\mathrm{S}{\mathrm{O}_4} + 2{\mathrm{H}_2}\mathrm{O} \to 2{\mathrm{H}_3}{\mathrm{O}^ + } + \mathrm{SO}_4^2$, then total number of ions produced by $\mathrm{0}\mathrm{.1}\;\mathrm{M}\;{\mathrm{H}_2}\mathrm{S}{\mathrm{O}_4}$ will be

Which of the following has the smallest number of molecules?

Assertion: The H-bonding of $\mathrm{NH}_3$ and $\mathrm{H}_2 \mathrm{O}$ is represented as:
${\text{H}} - \mathop {\text{O}}\limits_{\begin{array}{cccccccccccccccccccc} | \\ {\text{H}} \end{array}} - - - {\text{H}} - \mathop {\text{N}}\limits_{\begin{array}{cccccccccccccccccccc} | \\ {\text{H}} \end{array}} - {\text{H}}$
Reason: $\mathrm{H}_2 \mathrm{O}$ is more acidic than $\mathrm{NH}_3$ and thus, $\mathrm{H}_2 \mathrm{O}$ is a proton donor.

Reactants react in the equal number of …….. to give products.

What products are expected from the disproportionation reaction of hypochlorous acid

The relation between molecular weight $\left( M \right)$ and vapour density $\left( VD \right)$ is:

Molecular weight of tribasic acid is W. Its equivalent weight will be:

The prefix ${10^{ - 24}}$ is