List of practice Questions

The correct order of $pK _{ a }$ values for the following compounds is:

Decreasing order towards $SN 1$ reaction for the following compounds is:

Which of the following are the Green house gases?
A. Water vapour
B. Ozone
C. 1₂
D. Molecular hydrogen
Choose the most appropriate answer from the options given below

A flask contains hydrogen and oxygen in the ratio of $2: 1$ by mass at temperature $27^{\circ} C$ The ratio of average kinetic energy per molecule of hydrogen and oxygen respectively is:

An ice block floats in a liquid whose density is less than water. A part of block is outside the liquid. When whole of ice has melted, the liquid level will

Which waterways serve eastern Europe?

In a college, out of 4320 students, 2300 are girls. Find the ratio of
(a) Number of girls to the total number of students.
(b) Number of boys to the number of girls.
(c) Number of boys to the total number of students.

Cadets are marching in a parade. There are 5 cadets in a row. What is the rule which gives the number of cadets, given the number of rows? (Use n for the number of rows.)

The atomic numbers of elements A, B, D, E respectively are $7, 17, 13, 11$. The element which forms basic oxide among them is

In a village six fruit merchants sold the following number of fruit baskets in a particular season :

Observe this pictograph and answer the following questions :

Which merchant sold the maximum number of baskets?
How many fruit baskets were sold by Anwar?
The merchants who have sold 600 or more number of baskets are planning to buy a godown for the next season. Can you name them?

Raju purchases 10 pens for Rs. 150 and Manish buys 7 pens for Rs. 84. Can you say who got the pens cheaper?

When two resistors of resistances $ (123 \pm 2) \, \Omega $ and $ (227 \pm 4) \, \Omega $ are connected in series, then the value of equivalent resistance is:

Two bodies A and B are projected simultaneously with velocities $ 20 \, \text{ms}^{-1} $ and $ 40 \, \text{ms}^{-1} $, respectively. Body A is projected vertically up from the top of a tower of height 80 m and body B is projected vertically up from the bottom of the same tower. The bodies A and B meet in time of:

Complete the drawing shown in Fig. 9.14 to indicate where the free ends of the two wires should be joined to make the bulb glow

the two wires should be joined to make the bulb glow

Explain why a charged balloon is repelled by another charged balloon whereas an uncharged balloon is attracted by another charged balloon?

A light whose electric field vectors are completely removed by using a good polaroid, allowed to incident on the surface of the prism at Brewster’s angle. Choose the most suitable option for the phenomenon related to the prism.

Write a paragraph in your own words on each of the following.
1. Preparation of soil
2. Sowing
3. Weeding
4. Threshing

Complete the following reactions: $(i)$ $ {C2H5I + H2 ->[Zn - Cu][C_2H_5OH]} X$ $(ii)$ $ {CH3COONa + H2O ->[Electrolysis] Y }$ $(iii)$ $ {CH3CH2CH2CH2CH2CH3 ->[Cr_2O_3/Al_2O_3][773\,K] Z }$

If a closed organ pipe has the same third harmonic frequency as that of an open organ pipe, then their respective lengths are in the ratio

Top surface of a raised platform is in the shape of a regular octagon as shown in the figure. Find the area of the octagonal surface.

Name the following halides according to the IUPAC system and classify them as alkyl, allyl, benzyl (primary, secondary, tertiary), vinyl or aryl halides:
(i) $(CH_3)_2CHCH(Cl)CH_3$
(ii) $\text{CH}_3\text{CH}_2\text{CH}(\text{CH}_3)\text{CH}(\text{C}_2\text{H}_5)\text{Cl}$
(iii) $\text{CH}_3\text{CH}_2\text{C}(\text{CH}_3)_2\text{CH}_2\text{I}$
(iv) $(CH_3)_3CCH_2CH(Br)C_6H_5$
(v) $\text{CH}_3\text{CH}(\text{CH}_3)\text{CH(Br)CH}_3$
(vi) $\text{CH}_3\text{C(C}_2\text{H}_5)_2\text{CH}_2\text{Br}$
(vii) $\text{CH}_3\text{C(Cl)(C}_2\text{H}_5)\text{CH}_2\text{CH}_3$
(viii) $\text{CH}_3\text{CH}=C(Cl)\text{CH}_2\text{CH}(\text{CH}_3)_2$
(ix) $\text{CH}_3\text{CH}=CHC(Br)(\text{CH}_3)_2$
(x) $\text{p-ClC}_6\text{H}_4\text{CH}_2\text{CH}(\text{CH}_3)_2$
(xi) $\text{m-ClCH}_2\text{C}_6\text{H}_4\text{CH}_2\text{C(CH}_3)_3$
(xii) $\text{o-Br-C}_6\text{H}_4\text{CH(CH}_3\text{)CH}_2\text{CH}_3$

Fill in the blanks with the correct form of the verb in brackets.
(i) The heart is a pump that __(send) the blood circulating through our body. The pumping action__ (take place) when the left ventricle of the heart__ (contract). This __(force) the blood out into the arteries, which__ (expand) to receive the oncoming blood.
(ii) The African lungfish can live without water for up to four years. During a drought it__ (dig) a pit and__ (enclose) itself in a capsule of slime and earth, leaving a tiny opening for air. The capsule __(dry) and__ (harden), but when rain ___(come), the mud ____(dissolve) and the lungfish____ (swim) away.
(iii) MAHESH : We have to organise a class party for our teacher. ___(Do) anyone play an instrument?VIPUL : Rohit__ (play) the flute.
MAHESH : __(Do) he also act?
VIPUL : No, he ___(compose) music.
MAHESH : That’s wonderful!

How many images of a candle will be formed if it is placed between two parallel plane mirrors separated by 40 cm?

What will be the expression of K_p for the given reaction if the total pressure inside the vessel is P and degree of dissociation of the reactant is α? The reaction: N₂O₄ (g) ⇌ 2NO₂

Find the inverse of each of the matrices,if it exists.$\begin{bmatrix} 1 & 3 & -2\\ -3 & 0 & -5\\ 2&5&0 \end{bmatrix}$