Ncert Solutions Chemistry Class 11th

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option(C), (D)

The number of moles is given by the following formula,

Moles = $\frac{\mathrm{M}\mathrm{a}\mathrm{s}\mathrm{s}}{\mathrm{M}\mathrm{o}\mathrm{l}\mathrm{a}\mathrm{r}\mathrm{}\mathrm{m}\mathrm{a}\mathrm{s}\mathrm{s}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}}$  ---------------(1)

The number of molecules can be calculated as, number of moles

= $\frac{\mathrm{n}\mathrm{u}\mathrm{m}\mathrm{b}\mathrm{e}\mathrm{r}\mathrm{}\mathrm{o}\mathrm{f}\mathrm{}\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{e}\mathrm{c}\mathrm{u}\mathrm{l}\mathrm{e}\mathrm{s}}{\mathrm{A}\mathrm{v}\mathrm{o}\mathrm{g}\mathrm{a}\mathrm{d}\mathrm{r}\mathrm{o}\mathrm{}\mathrm{s}\mathrm{n}\mathrm{u}\mathrm{m}\mathrm{b}\mathrm{e}\mathrm{r}\mathrm{}}$  ----------(2)

(C) The number of moles of N₂ is calculated by

This is a Multiple Choice Questions as classified in NCERT Exemplar

The answers are options (i) and (ii)

(A)The number of moles is given by the following formula,

Moles = $\frac{\mathrm{M}\mathrm{a}\mathrm{s}\mathrm{s}}{\mathrm{M}\mathrm{o}\mathrm{l}\mathrm{a}\mathrm{r}\mathrm{}\mathrm{m}\mathrm{a}\mathrm{s}\mathrm{s}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}}$

So, the number of moles of NaOH is calculated, by using equation (1) as follows

 20 g NaOH in 200 mL solution.

Moles of NaOH=

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option(C), (D)

(A) The number of moles is given by the following formula,

Moles = $\frac{\mathrm{M}\mathrm{a}\mathrm{s}\mathrm{s}}{\mathrm{M}\mathrm{o}\mathrm{l}\mathrm{a}\mathrm{r}\mathrm{}\mathrm{m}\mathrm{a}\mathrm{s}\mathrm{s}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}}\mathrm{}$ -----------(1)

The number of moles of O₂ is calculated by using equation (1) as follows,

Moles of O₂ = $\frac{16\mathrm{}\mathrm{g}}{32\mathrm{}\mathrm{g}\mathrm{}/\mathrm{}\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{}\mathrm{}\mathrm{}\mathrm{}\mathrm{}}$  = 0.5 mol

The number of atoms can be calcul

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (B), (C)

0.1 mole H₂SO₄ reacts with 1 mole of NaOH.

0.1 mole of NaOH will react with $\frac{0.1}{2\mathrm{}\mathrm{}}$ = mole of H₂SO₄

Here, NaOH is the limiting reagent.

2 mole of NaOH produces 1 mole of Na₂SO₄

0.1 mole of NaOH will give $\frac{0.1}{2\mathrm{}\mathrm{}}$  mole of Na₂SO₄

No

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (A), (D)

One mole of oxygen gas at STP is equal to  6.022 x 10²³  molecules of oxygen The number of moles is given by the following formula,

Moles = $\frac{\mathrm{M}\mathrm{a}\mathrm{s}\mathrm{s}}{\mathrm{M}\mathrm{o}\mathrm{l}\mathrm{a}\mathrm{r}\mathrm{}\mathrm{m}\mathrm{a}\mathrm{s}\mathrm{s}\mathrm{}\mathrm{}}$    ----------(1)

The number of moles of O₂ is calcula

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (B)

Law of multiple proportion: According to the law of multiple proportion, whe form two or more than two chemical compounds, the ratio between different elements combining with a fixed mass of the other is always in the ratio

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (B)

In a, c, and d options given reactions, all the elements are balanced and hence, following the law of conservation of mass.

In reaction (B), C₃H₈+ O₂→ CO₂+H₂0  elements are not balanced. Hence product are different. It

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Ans: option  (iii)

According to Heisenberg's uncertainty principle it is impossible to determine simultaneously, the exact position and exact momentum (or velocity) of an electron. Thus, it implies that determining the

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (A)

According to the law of conservation of mass, matter can neither be created nor be destroyed. In the given reaction,

4Fe + 3O₂→ 2Fe₂O₃

The mass of reactant is equal to the mass of product. Hence, it follows the law of conser

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Ans: option (ii)

The black body is the ideal body that absorbs and emits radiation of all frequencies. The radiation that it emits is said to be black body radiation. With an increase of temperature, the frequency of the bla