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20 questions
The figure given below represents the experiment carried out between conc. sulphuric acid and sodium chloride, which react with each other to form HCl gas.
Blue litmus paper is brought near the mouth of the delivery tube to check the presence of HCl acid but no change is observed in the color of litmus paper because:
The litmus paper used is dry
The litmus paper used is moist
Blue litmus paper does not change its color with an acid
The litmus paper is kept very close to the mouth of the delivery tube
Which of the following indicators turn red in an acidic solution?
i. Phenolphthalein
ii. Litmus
iii. Turmeric
iv. Methyl orange
Choose the correct option:
(i) and (ii)
(ii) and (iii)
Only (ii)
(ii) and (iv)
Which of the following salt will give acidic solution when dissolved in water?
NH4Cl
NaCl
Na2CO3
CH3COONa
Copper sulphate crystals when heated strongly, lose their water of crystallization to give anhydrous copper sulphate accompanied by a change in color from:
Blue to green
Blue to white
Blue to sky blue
Blue to grey
Dilute acid does not produce carbon dioxide on being treated with:
Marble
Lime
Baking soda
Limestone
Tick the correct matched column
(a) —> (i) (b) —> (iii) (c) —> (ii) (d) —> (iv)
(a) —> (i) (b) —> (ii) (c) —> (iii) (d) —> (iv)
(a) —> (iv) (b) —> (iii) (c) —> (ii) (d) —> (i)
None of these.
Identify X ?
NaOCl
NaOH
NaO
Na2 OH
The pH of the gastric juices released during digestion is
less than 7
more than 7
equal to 7
equal to 0
Which of the following is used for dissolution of gold?
Hydrochloric acid
Sulphuric acid
Nitric acid
Aqua regia
Some fruits like mango, lemon, raw grapes, orange, etc., have a sour taste due to the presence of:
Acetic acid
Citric acid
Lactic acid
Oxalic acid
A pair of linear equations a1x + b1y + c1 = 0; a2x + b2y + c2 = 0 is said to be inconsistent, if
a
b
c
d
Graphically, the pair of equations 7x – y = 5; 21x – 3y = 10 represents two lines which are
intersecting at one point
parallel
intersecting at two points
coincident
For what value of k, do the equations 2x – 3y + 10 = 0 and 3x + ky + 15 = 0 represent coincident lines
a
b
c
d
One equation of a pair of dependent linear equations is 2x + 5y = 3. The second equation will be
2x + 5y = 6
3x + 5y = 3
-10x – 25y + 15 = 0
10x + 25y = 15
The graph of x = -2 is a line parallel to the
x-axis
y-axis
both x- and y-axis
none of these
If in the equation x + 2y = 10, the value of y is 6, then the value of x will be
The value of k, for which equations 3x + 5y = 0 and kx + lOy = 0 has a non-zero solution is
The father’s age is six times his son’s age. Four years hence, the age of the father will be four times his son’s age. The present ages of the son and the father are, respectively
3 and 24
5 and 30
6 and 36
4 and 24
The sum of the digits of a two-digit number is 9. If 27 is added to it, the digits of the number get reversed. The number is
Asha has only ₹1 and ₹2 coins with her. If the total number of coins that she has is 50 and the amount of money with her is ₹75, then the number of ₹1 and ₹2 coins are, respectively
35 and 15
15 and 35
35 and 20
25 and 25
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