The number of water molecules present in a drop of water weighing 0.018 g is
6.022 × 1026
6.022 × 1023
6.022 × 1019
6.022 × 1020
Empirical formula of a compound is CH2O and its molecular mass is 90, the molecular formula of the compound is
C3H6O3
C2H4O2
C6H12O6
CH2O
Hybridised states of carbon in graphite and diamond are respectively
sp3, sp3
sp3, sp2
sp2, sp2
sp2 , sp3
The yield of the products in the reaction A2(g) + 2B(g) C(g) + kJ would be higher at
high temperature and high pressure
high temperature and low pressure
low temperature and high pressure
low temperature and low pressure
Given thermochemical equation, 2H2 (g) + O2(g) → 2H2O,ΔH = -571.6 kJ. Heat of decomposition of water is
-571.6 kJ
+571.6 kJ
-1143.2 kJ
+ 285.8 kJ
An example for a neutral buffer is
ammonium hydroxide and ammonium chloride
acetic acid and sodium acetate
acetic acid and ammonium hydroxide
citric acid and sodium citrate