22.2%
14.8%
7.4%
3.7%
Correct answer is B
. % of C in Ca(HCO3)2
Molar mass of Ca(HCO3)2 = 40+(1+12+(16*3))2
=40+(13+48)2
=40+122
=162
C/Ca(HCO3)2 x 100
=12 * 2/162 * 100
=14.8%
Which of the following elements would displace copper from a solution of copper ions?
silver
gold
lead
mercury
Correct answer is C
The reactivity series allows us to predict how metals react. A more reactive metal displaces a less reactive metal from a compound. Lead is more reactive metal than copper hence, copper is displaced from copper solution by lead.
1.0 mol dm\(^{-3}\)
1.5 mol dm\(^{-3}\)
2.0 mol dm\(^{-3}\)
5.0 mol dm\(^{-3}\)
Correct answer is A
V= 50cm\(^{3}\)
Mass= 5.05g
Relative molecular mass of KNO\(_{3}\) = (39+14+(3*16)) = 101
Convert 50cm\(^{3}\) to dm\(^{3}\) which is
1000cm³ = 1dm\(^{3}\)
50cm³ = 50*1/1000
= 0.05dm\(^{3}\)
Moles = mass/ molar mass
= 5.05/101 =0.05mole
Solubility= mole/volume
Solubility=0.05mol/0.05dm\(^{3}\)
Solubility=1.0mol/dm_\(^{3}\)
0.32
1.52
3.13
31.25
Correct answer is C
P = 10atm, T= 320K, V= 8.2dm\(^{3}\)
PV =nRT
n = P * V/R * T
10 * 8.2/0.082 * 320
= 82/26.24
n = 3.13
1:3
2:1
3:1
4:1
Correct answer is B
4HCl + O\(_{2}\) -- 2Cl\(_{2}\) + 2H\(_{2}\)O
4:2 = 4/2
2:1