A molar solution of caustic soda is prepared by dissolving
40 g NaOH in 100 g of water
40 g NaOH in 1000 g of water
20 g NaOH in 500 of solution
20 g NaOH in 1000 g of solution
20 g NaOH in 80 g of solution
Correct answer is B
A molar solution implies concentration in terms of moles/liter. The respective atomic weights for NaOH are: Na - 23,0 - 16 and H - 1, so the molecular weight, is 23 + 16 + I = 40. Thus 40 grams of NaOH equals one mole of NaOH, and a 1 molar solution of NaOH will contain 40 grams of NaOH chemical in 1000grams of water.
2.24 dm 3
2.24 cm3
1. 123
1. 12dm 3
4. 48 dm 3
Correct answer is D
\(NH_{4}NO_{2}\) \(\to\) \(N_{2}\) + \(2H_{2}O\)
\(64g\) \(\to\) \(22.4dm^{3}\)
\(3.2g\) will give \(\frac{22.4}{64}\) \(\times\) \(\frac{3.2}{64}\)
= \(1.12dm^{3}\)
40 cm 3
20 cm 3
30 cm 3
10cm 3
5cm 3
Correct answer is D
2H2 + O2 ------2H2O
2V 1V 2V
20cm3 20cm3 -------
20cm3 10cm3 20cm3
Residual gas = 20cm3 - 10cm3 of 02 = 103
Sodium chloride may be obtained from brine by
titration
decantation
distillation
evaporation
sublimation
Correct answer is D
No explanation has been provided for this answer.
X and Z
Y
X
Z
Correct answer is C
Aromatic compounds burn with a yellow sooty flame and they don't decolorise bromine water, since bromine is not electrophilic enough except in the presence of a strong Lewis catalyst.