250 mL of a sodium carbonate solution contains 2.65 g of Na2CO3. If 10 mL of this solution is diluted to one litre, what is the concentration of the resultant solution ?
0.1 M
0.001 M
0.01 M
10-4 M
How many litres of oxygen (at STP) are required for complete combustion of 39 g of liquid benzene? (Atomic weights: C = 12, O = 16, H = 1).
84
22.4
42
11.2
X litre of carbon monoxide is present at STP. It is completely oxidized to CO2. The volume of CO2 formed is 11.207 litres. What is the value of X in litres?
22.414
11.207
5.6035
44.828
The concentration of a 100 mL solution containing X g of Na2CO3 (molecular wt. = 106) is Y M. The values of X and Y are respectively.
2.12, 0.05
1.06, 0.2
1.06, 0.1
2.12, 0.1
One mole of fluorine is reacted with two moles of hot concentrated KOH. The products formed are KF, H2O and O2. The molar ratio of KF, H2O and O2 , respectively is
1 : 1 : 2
2 : 1 : 0.5
1 : 2 : 1
2 : 1 : 2
The electrochemical equivalent of a metal is 'x' g coulomb-1. The equivalent weight of metal is
x
x × 96500
1.6 × 1019 × x
x grams of water is mixed in 69 g of ethanol. Mole fraction of ethanol in the resultant solution is 0.6. What is the value of x in grams?
54
36
180
18
D.
18
wA = x gm; mA = 18; XA = 1 - 0.6 = 0.6
wB = 69 gm; mB = 46; XB = 0.4
We know that,
XA =
or,
0.4 =
0.4 =
or, 2x + 54 = 5x
or, 3x = 54
or, x = 18 gm
An organic compound containing C and H has 92.3% of carbon. Its empirical formula is
CH
CH3
CH2
CH4
x grams of calcium carbonate was completely burnt in air. The weight of the solid residue formed is 28 g. What is the value of x (in grams)?
44
200
150
50
The concentration of oxalic acid is 'x' mol L-1. 40 mL of this solution reacts with 16 mL of 0.05 M acidified KMnO4. What is the pH of 'x' M oxalic acid solution ? (Assume that oxalic acid dissociates completely)
1.3
1.699
1
2