Some basic concepts of chemistry practice · Mixed difficulty

The net charge on ferrous ion is:

1 mol each of ${H}_3 {PO}_2, {H}_3 {PO}_3$ and ${H}_3 {PO}_4$ will neutralize $x \mathrm{~mol}$ of ${NaOH}, y \mathrm{~mol}$ of ${Ca}({OH})_2$ and ${z} \mathrm{~mol}$ of ${Al}({OH})_3 . x, y$ and $z$ are in the ratio

Which represents per cent by weight?

If 65.5 g of a metal chloride contains 35.5 g chlorine, then equivalent mass of metal is

Hydrogen peroxide in aqueous solution decomposes on warming to give oxygen according to the equation, $2{\mathrm{H}_2}{\mathrm{O}_2}\left( {aq} \right) \to 2{\mathrm{H}_2}\mathrm{O}\left( l \right) + {\mathrm{O}_2}\left( \mathrm{g} \right)$ under conditions where one mole of gas occupies 24 $\mathrm{d}{\mathrm{m}^3},100\mathrm{c}{\mathrm{m}^3}$ of $XM$ solution of ${\mathrm{H}_2}{\mathrm{O}_2}$ produces 3 $\mathrm{d}{\mathrm{m}^3}$ of ${\mathrm{O}_2}$. Thus, $X$ is :

A transition metal $M$ forms a volatile chloride which has a vapour density of 94.8 . If it contains $74.75 \%$ of chlorine the formula of the metal chloride will be

The density of $3 \mathrm{M}$ solution of sodium chloride is $1.252 \mathrm{~g} \mathrm{~mL}^{-1}$. The molality of the solution will be:

(molar mass, $\mathrm{NaCl}=58.5 \mathrm{~g} \mathrm{~mol}^{-1}$ )

In the given chemical reaction, colours of the $\mathrm{F}{\mathrm{e}^{\mathrm{2 + }}}\,\,\mathrm{and}\,\,\mathrm{ F}{\mathrm{e}^{\mathrm{3 + }}}$ ions, are respectively
$\mathrm{5}F{e^{\mathrm{2 + }}}\mathrm{ + }M\mathrm{n}O_4^ - + 8{H^ + } \to M{n^{2 + }} + 4{H_2}O + 5F{e^{3 + }}$

50 mL of an aqueous solution of glucose contains $6.02 \times {10^{22}}$ molecules. The concentration of solution is:

Mass of one molecule of glucose is $\left(\mathrm{N}_{\mathrm{A}}=6 \times 10^{23}\right)$

For the reaction :

$\mathrm{H}_3 \mathrm{PO}_3+\mathrm{Ba}(\mathrm{OH})_2 \rightarrow \mathrm{BaHPO}_3+2 \mathrm{H}_2 \mathrm{O}$

The correct statement(s) is/are

(a) The equivalent mass of $\mathrm{H}_3 \mathrm{PO}_3$ is 41.

(b) $\mathrm{BaHPO}_3$ is the acid salt

(c) $\mathrm{BaHPO}_3$ is normal salt

(d) 1 mole of $\mathrm{H}_3 \mathrm{PO}_3$ is completely neutralized by 1.5 moles of $\mathrm{Ba}(\mathrm{OH})_2$

Chlorofluorocarbons such as ${CCl}_3 {F}(\mathrm{M}=137.5)$ and ${CCl}_2 {F}_2(\mathrm{M}=121)$ have been linked to ozone depletion in Antarctica. As of 2004, these gases were found in 275 and 605 parts per trillion $\left(10^{12}\right),$ by volume. What are the concentrations of these gases under conditions typical of Antarctica stratosphere $(200 \mathrm{~K}$ and $0.08 \mathrm{~atm}) ?(R=0.08 \, l \text{-atm/K-mol})$

$100 \mathrm{~mL}$ of $\mathrm{N} / 5 \mathrm{NaOH}$ will neutralize

25 mL of 0.50 $M{\mathrm{H}_2}{\mathrm{O}_2}$ solution is added to 50 mL of 0.20 M $M\mathrm{KMn}{\mathrm{O}_4}$ in acidic solution. Which of the following statements is true?

The number of gram atoms of oxygen present in 0.3 gram mole of $({COOH})_2 \cdot 2 {H}_2 {O}$ is

The mineral haematite is $\mathrm{Fe}_2 \mathrm{O}_3$. Haematite ore contains unwanted material called gangue in addition of $\mathrm{Fe}_2 \mathrm{O}_3$. If $5.0 \mathrm{~kg}$ of ore contains $2.78 \mathrm{~kg}$ of $\mathrm{Fe}$, what per cent of ore is $\mathrm{Fe}_2 \mathrm{O}_3$?

If the weight of metal oxide is ${xg}$ containing ${yg}$ of oxygen, the equivalent weight of metal will be

When $10 \mathrm{~ml}$ of acetic acid (density $=0.8 \mathrm{~g} / \mathrm{ml}$) is mixed with $40 \mathrm{~ml}$ of water (density $=1 \mathrm{~g} / \mathrm{ml}$) at a certain temperature, the final solution is found to have a density of $\frac{96}{98} \mathrm{~g} / \mathrm{ml}.$ The percent change in total volume on mixing is

At NTP 2.24L of a gas weight $3.65 \mathrm{~g}$. The mole of the gas in $18.25 \mathrm{~g}$ is :-

If $m_A$ gram of a metal $A$ displaces $m_B$ gram of another metal $B$ from its salt solution and if the equivalent weights are $E_A$ and $E_B$ respectively then equivalent weight of $A$ can be expressed as:

$40 \mathrm{ml}$ of $0.8 \mathrm{~N}$ oxalic acid dihydrate is shaken with $0.75 \mathrm{~g}$ active charcoal. The final concentration of the solution after adsorption is $0.2 \mathrm{~N}$. What is the amount of oxalic acid adsorbed per gm of carbon?

Assertion (A) : In the following half reaction:
$\mathrm{Cr}_2 \mathrm{O}_7^{2-} \longrightarrow \mathrm{Cr}^{3+}$
Equivalent weight of $\mathrm{Cr}_2 \mathrm{O}_7^{2-}=\frac{\text { Molar mass }}{3}$
Reason (R) : Change in oxidation number of chromium is 3 per atom.

What is the weight of oxygen required for the complete combustion of 2.8 kg of ethylene

What is the mass of $3.01 \times 10^{22}$ molecules of ammonia?

An amount of 5 moles of $\text{A,}$ 6 moles of $\text{B}$ and excess amount of $\mathrm{C}$ are mixed to produce a final product $\mathrm{D}$, according to the following reactions.

$\begin{aligned} & \mathrm{A}+2 \mathrm{B} \rightarrow \mathrm{I} \\ & \mathrm{I}+\mathrm{C} \rightarrow \mathrm{B}+\mathrm{D} \end{aligned}$

What is the maximum moles of $\mathrm{D},$ which can be produced assuming that the products formed can also be reused in the reactions?

In the following reaction, $\mathrm{As}_2 \mathrm{~S}_3+\mathrm{H}^{+}+\mathrm{NO}_3^{-} \longrightarrow \mathrm{NO}+\mathrm{H}_2 \mathrm{O}+\mathrm{AsO}_4^{3-}+\mathrm{SO}_4^{2-}$ the equivalent weight of $\mathrm{As}_2 \mathrm{~S}_3$ is related to its molecular weight by :

Assertion (A) : 1 mole of $\mathrm{FeC}_2 \mathrm{O}_4$ is oxidised by 0.6 mole of $\mathrm{MnO}_4^{-}$in acidic medium.

Reason (R) : $\mathrm{MnO}_4^{-}$oxidises both $\mathrm{Fe}^{2+}$ as well as $\mathrm{C}_2 \mathrm{O}_4^{2-}$.

Cupric ammonium sulphate was found to contain
$27.03\%$ water of crystallization by mass. Upon
strongly heating, it gave cupric oxide corresponding
to $19.89\%$ of starting mass. Find the empirical
formula of cupric ammonium sulphate. $(\text{Cu} = 63.5)$

Mole fraction of solute in an aqueous solution of $\mathrm{NaOH}$ is $0.1.$ If the specific gravity of the solution is $1.4,$ then the molarity of the solution is

The element $\mathrm{Q}$ has the following isotopic composition, $\mathrm{Q}^{200}: 80 \%; \mathrm{Q}^{190}: 15 \%$ and $\mathrm{Q}^{210}: 5 \%$. The average atomic mass of the naturally occurring element $\mathrm{Q}$ is