Some basic concepts of chemistry practice · Mixed difficulty

The equivalent weight of an element can be calculated from:

What weight of $\mathrm{HN}{\mathrm{O}_3}$ is required to make 1 litre of 2 N solution to be used as an oxidising agent in the reaction? $3\mathrm{Cu} + 8\mathrm{HN}{\mathrm{O}_3} \to 3\mathrm{Cu}{\left( {\mathrm{N}{\mathrm{O}_3}} \right)_2} + 2\mathrm{NO} + 4{\mathrm{H}_2}\mathrm{O}$

Equivalent weight of a bivalent metal is 37.2. The molecular weight of its chloride is

A crystalline hydrated salt on being heated loses $45.6 \%$ of its weight. Percentage composition of anhydrous salt is $Al$ - $10.5 \%, {K}-15.1 \%$, $S-24.8 \%,\, {O}-49.6 \%$. Find molecular formula of salt (hydrated) $({M}=948 \mathrm{~g} / \mathrm{mol}$ for hydrated salt).

The number of equivalent per mole of ${\mathrm{H}_2}\mathrm{S}$ used in its oxidation to $\mathrm{S}{\mathrm{O}_2}$ is :

If average molecular wt. of air is 29 , then assuming $\mathrm{N}_2$ and $\mathrm{O}_2$ gases are there which options are correct regarding composition of air:

(i) $75 \%$ by mass of $\mathrm{N}_2$

(ii) $75 \%$ by moles $\mathrm{N}_2$

(iii) $72.41 \%$ by mass of $\mathrm{N}_2$

When a solid vaporizes directly without melting, it is known as:

100 mL of 0.1 M solution of a reductant is diluted to 1 litre, which of the following changes?

6.90 grams of metal carbonate was completely decomposed by 50 ml of 2N HCl. The equivalent weight of metal is

Assertion: The atomic mass of an element is given by Dulong-Petit's law: atomic mass $\times$ sp. heat $(\mathrm{cal} / \mathrm{mol}) \simeq 6.4$.
Reason: The formula is valid for metals only and not for all elements.

Which of the following pairs contains equal number of atoms?

Assertion : A certain element $X$, forms three binary compounds with chlorine containing $59.68 \%, 68.95 \%$ and $74.75 \%$ chlorine respectively. These data illustrate the law of multiple proportions.

Reason : According to law of multiple proportions, the relative amounts of an element combining with some fixed amount of a second element in a series of compounds are the ratios of small whole numbers.

Which mode of expressing concentration is independent of temperature?

Which of the following is an SI unit?

Cortisone is a molecular substance containing 21 atoms of carbon per molecule. The molecular weight of cortisone is 360.4. what is the percentage of carbon in cortisone?

One mole of $\;\mathrm{C}{\mathrm{O}_2}$ contains:

Molecular mass is defined as the

The prefix ${10^{18}}$ is

In alkaline medium, the reduction of permanganate anion involves a gain of_____electrons.

Which represents per cent by weight?

The prefix zepto stands for (in m)

Among the following statements, that which was not proposed by Dalton was

Which of the following reactions is not correct according to the law of conservation of mass.

A 10g sample of $CaC{O_3}$ with 80% purity was heated to a constant weight volume of $C{O_2}$ gas liberated under STP conditions is approximately

With increase of temperature, which of these changes?

How many mole of atoms are in a mole of $\mathrm{C}{\mathrm{H}_3}\mathrm{COOH}$ molecule?

Dulong and Petit’s law is valid only for

Assertion:- Law of conservation of mass hold good for nuclear reaction.

Reason:- Law states that mass can be neither created nor destroyed in a chemical reaction.

What weight of $\mathrm{HN}{\mathrm{O}_3}$ is needed to convert 5 g of iodine into iodic acid according to the reaction, ${\mathrm{I}_2} + \mathrm{HN}{\mathrm{O}_3} \to \mathrm{HI}{\mathrm{O}_3} + \mathrm{N}{\mathrm{O}_2} + {\mathrm{H}_2}\mathrm{O}?$ ?

A gaseous mixture contains oxygen and nitrogen in the ratio of $1:4$ by weight. Therefore, the ratio of their number of molecules is: