Answer: Mothballs have weak intermolecular forces.
No all substances do not behave like mothballs at normal conditions. Example: benzene , chloroform
Explanation:
Sublimation is a process of converting a substance from solid state to gaseous state without the formation of liquid at constant temperature.
A substance which undergoes sublimation is called as sublimating substance.
As mothballs is made of napthalene which has weak inter molecular forces of attraction between its molecules, it directly sublimes into gaseous state without leaving any residue and is called as a sublimating substance.
Not all substances behave like mothballs at normal conditions. Example: benzene , chloroform
Reaction for precipitation is
Pb(NO3)2(aq) + 2Nacl(aq)→PbCL2(s)+2NaNO3(aq)
The given reaction is
The mol of Nacl required is =2×mol of Pb(NO3)2 which is present.
∴M(Nacl)×V(Nacl) =2×M(Pb(NO3)2 ×V(Pb(NO3)2
o.100M×V(Nacl)=2×0.200 MX75.0ML
V(Nacl = 300mL.
Answer:
% Ca = 24.69%
% H = 1.2%
% C = 14.8%
% O = 59.25%
Explanation:
The percentage by mass of each element can be calculated by dividing the mass of each element in the compound by the molar mass of the compound.
Molar mass of Ca(HCO3)2
Where; (Ca= 40, H = 1, O = 16, C= 12)
= 40 + {1 + 12 + 16(3)}2
= 40 + {13 + 48}2
= 40 + {61}2
= 40 + 122
= 162g/mol
- % mass of Ca = 40/162 × 100
= 0.2469 × 100
= 24.69%
- % mass of H = 2/162 × 100
= 0.012 × 100
= 1.2%
- % mass of C = 24/162 × 100
= 0.148 × 100
= 14.8%
- % mass of O = 96/162 × 100
= 0.5925 × 100
= 59.25%
Answer:
Option A. FeCl3
Explanation:
The following data were obtained from the question:
Mass of iron (Fe) = 6.25g
Mass of the compound formed = 18g
From the question, we were told that the compound formed contains chlorine. Therefore the mass of chlorine is obtained as follow
Mass of chlorine (Cl) = Mass of compound formed – Mass of iron.
Mass of chlorine (Cl) = 18 – 6.25
Mass of chlorine (Cl) = 11.75g
The compound therefore contains:
Iron (Fe) = 6.25g
Chlorine (Cl) = 11.75g
The empirical formula for the compound can be obtained by doing the following:
Step 1:
Divide by their molar mass
Fe = 6.25/56 = 0.112
Cl = 11.75/35.5 = 0.331
Step 2:
Divide by the smallest
Fe = 0.112/0.112 = 1
Cl = 0.331/0.112 = 3
The empirical formula for the compound is FeCl3
