Download App

Chemistry M.C.Q (1 Marks)

MODEL PAPER 2 · Rajasthan Board (RBSE) STD 12 Science (Rajasthan - English Medium). 12 questions.

Questions

M.C.Q (1 Marks)

Take a timed test

12 questions · self-marked practice — reveal the answer and mark yourself.

Question 11 Mark
DNA fingerprinting means the
Answer
(c) information regarding the unique sequence of bases on DNA for a person
Explanation: A sequence of bases on DNA is unique for a person and information regarding this is called DNA fingerprinting. It is same for every cell and cannot be altered by any known treatment.
View full question & answer→
Question 21 Mark
Match the items of column I with appropriate entries of column $II.$
Column $I$ Column $II$
$(a) \frac{\Delta P }{ P ^{\circ}{ }_A}$ $(i) \frac{\Delta T _{ b }}{ m }$
$(b)\ K_b$ $(ii)$ mol fraction of solute
$(c)\ i$ $(iii) \frac{\Delta T _{ f }}{ m }$
$(d)\ K_f$ $(iv)$ Ratio of observed molar mass to actual molar mass
Answer
$(a) - (ii), (b) - (i), (c) - (iv), (d) - (iii)$
View full question & answer→
Question 31 Mark
How to do the following conversion:
$RCOOCI + ? \rightarrow RCHO$
Answer
Catalytic hydrogenation of acid chloride using $H_2-Pd, BaSO_4$ converts acid chloride selectively to aldehydes $(BaSO_4$ reduces the activity of palladium$).$ This is known as Rosenmund Reduction.
Image
View full question & answer→
Question 41 Mark
One mole of an organic compound $'A\ '$ with the formula $C_3H_8O$ reacts completely with two moles of $HI$ to form $X$ and $Y.$ When $'Y\ '$ is boiled with aqueous alkali forms $Z.\ Z$ answers the iodoform test. The compound $'A\ '$ is ________
Answer
Ether reacts with HI to form alcohol and alkyl iodide. Alcohol on oxidation will give the iodoform test.
View full question & answer→
Question 51 Mark
The correct increasing order of basic strength for the following compounds is __________ .
Image
Answer
(b) 5-Chlorohexan - 2 - ol
Image
-OH is given preference over -Cl so numbering is done so that -OH gets the lowest number.
View full question & answer→
Question 61 Mark
The slope of the line in the plot of concentration [A] Vs. time (s) indicate
Answer
(b) -k
Explanation: Slop of the line indicates = -k while the intercept represents [R]0.
View full question & answer→
Question 71 Mark
Carbon tetrachloride has a dipole moment:
Answer
$\mu = 0$
$CCl_4$ is a symmetrical molecule. Hence, the dipole moment is zero.
View full question & answer→
Question 81 Mark
If $75\%$ of a first order reaction was completed in $32 \min,$ then $50\%$ of the reaction was completed in $...... .$
Answer
$(c)\ 16 \min$
Explanation : $75\%$ completion means $2$ half lifes so $50\%$ completion means only one half life.
$k=\frac{2.303}{t} \log \frac{a}{a-x}$
$k=\frac{2.303}{32} \log \left(\frac{100}{100-75}\right) \ldots(1)$
$k=\frac{2.303}{t} \log \left(\frac{100}{100-50}\right) \ldots(2)$
from $(1)$ and $(2),$ we get
$t = 16 \min $
View full question & answer→
Question 91 Mark
Among the following, which bivalent ion of the first transition series shows a maximum magnetic moment?
Answer
$Mn^{2+}$ has $d^5$ configuration so a maximum number of unpaired electrons and hence maximum magnetic moment. This magnetic moment can be calculated by using the spin only formula: $µ_{so} = \angle n(n+2),$ where $n=$ number of unpaired electrons.
View full question & answer→
Question 101 Mark
The order of reactivity of following alcohols with halogen acids is ______.
Image
Answer
(b) (C) > (B) > (A)
Explanation: Haloalkanes are prepared from alcohol and halogen acids where the hydroxyl group of the alcohol is replaced by the halogen. Options (A) (B) and (C) are primary, secondary, tertiary alcohols respectively. Tertiary alcohols are more reactive than secondary and primary alcohol, the secondary halide is more reactive than primary halide and they form haloalkanes from haloacids at room temperature without catalysts. The order of reactivity of alcohols is 3°>2°>1°.
View full question & answer→
Question 111 Mark
Give IUPAC name of the compound given below.
Image
Answer
(d) II < I < III
Image
Electron withdrawing group decreases the basic strength of aniline while electron releasing groups increases the basic strength of aniline.
View full question & answer→
Question 121 Mark
The common name for pentanedioic acid is:
Answer
$\rightarrow$ Pentanedioic acid is known as glutaric acid.
$\rightarrow (COOH)_2$ is known as oxalic acid.
$\rightarrow$ Butanedioic acid is known as succinic acid.
$\rightarrow$ Hexanedioic acid is known as adipic acid.
$\rightarrow$ Heptanedioic acid is known as pimelic acid.
View full question & answer→
Generate Paper FreeAll MODEL PAPER 2 topics
M.C.Q (1 Marks) - Chemistry STD 12 Science Questions - Vidyadip