DAT CHEMISTRY - PRACTICE QUESTIONS
WITH DETAILED VERIFIED ANSWERS
.Which has a linear molecular geometry?
a) PCl3
b) CH3Cl
c) XeF2
d) H2O
e) O3 - correct answer- XeF2
0.85g toluene is used to depress the freezing point of 100g of
benzene by 0.50 degrees C (Kf benzene = 5 degrees/m) What is
the estimated molar mass of toluene? - correct answer-
deltaTf = -ikm
i=1
solve for molality:
m = deltat/ik
m = 0.5/(1)(5)
Find moles from molality equation:
,m = moles/mass
moles = mass x m
moles = (0.1)(0.1) = 0.01
Finally, find molar mass: mass/moles = 0.85/0.01 = 85 g/mol
75g of MgCl2 is dissolved in 150g of water. What is the molality
of this solution? - correct answer- molality = moles of
solute/ kg of solvent
1. Find moles: molar mass of MgCl2 = 95g/mol
= mass/molar mass
= 75g/95g ~ 0.75
2. Convert to kg
150g = 0.15kg
3. Solve for molality
0.75/0.15 = ~ 5
,A 200g sample of mercury at 25 degrees C was heated to 75 with
3kJ of energy. Calculate specific heat capacity of mercury in J/g
degreesC - correct answer- q = mcdeltaT
3000J = (200g)(c)(75-25)
c = 3000/(200)(50)
A 35g sample of metal alloy at 25 degrees absorbs 2.5kJ of
energy and as a result, is heated to 35 degrees. Calculate specific
heat of alloy in J/g. - correct answer- q = mcdeltaT
2500J = (35)(c)(35-25)
2500/(35)(10) = c
A 50mL solution of 6M HCl is diluted to 1.95L. What is the
molarity of the resulting solution? - correct answer-
M1V1=M2V2
M2=(6)(0.05L)/1.95
0.30/1.95 = ~0.15 M
, A botanist has discovered a new plant and notes that it is
predominantly found in its gametophyte form. Which category
does this plant most likely belong to?
a) Bryophyte
b) Angiosperm
c) Gymnosperm
d) Seedless tracheophyte
e) Endosperm - correct answer- Bryophyte
Tracheophyte are mostly sporophyte (includes angiosperms,
seedless tracheophytes and gymnosperms)
A chemical compound X decomposes with a half life of 3 hours.
Suppose there are 20 grams of X in a container. How long will it
take for only 5 grams of X to be left in the container? - correct
answer- 20/2 = 10
10/2 = 5
therefore, 2 half lives
2 x 3 = 6 hours
A container holds 4.0L of gas at 3.5 atm and a temp of 27
degrees C. If the pressure is reduced to 0.8 atm without a
WITH DETAILED VERIFIED ANSWERS
.Which has a linear molecular geometry?
a) PCl3
b) CH3Cl
c) XeF2
d) H2O
e) O3 - correct answer- XeF2
0.85g toluene is used to depress the freezing point of 100g of
benzene by 0.50 degrees C (Kf benzene = 5 degrees/m) What is
the estimated molar mass of toluene? - correct answer-
deltaTf = -ikm
i=1
solve for molality:
m = deltat/ik
m = 0.5/(1)(5)
Find moles from molality equation:
,m = moles/mass
moles = mass x m
moles = (0.1)(0.1) = 0.01
Finally, find molar mass: mass/moles = 0.85/0.01 = 85 g/mol
75g of MgCl2 is dissolved in 150g of water. What is the molality
of this solution? - correct answer- molality = moles of
solute/ kg of solvent
1. Find moles: molar mass of MgCl2 = 95g/mol
= mass/molar mass
= 75g/95g ~ 0.75
2. Convert to kg
150g = 0.15kg
3. Solve for molality
0.75/0.15 = ~ 5
,A 200g sample of mercury at 25 degrees C was heated to 75 with
3kJ of energy. Calculate specific heat capacity of mercury in J/g
degreesC - correct answer- q = mcdeltaT
3000J = (200g)(c)(75-25)
c = 3000/(200)(50)
A 35g sample of metal alloy at 25 degrees absorbs 2.5kJ of
energy and as a result, is heated to 35 degrees. Calculate specific
heat of alloy in J/g. - correct answer- q = mcdeltaT
2500J = (35)(c)(35-25)
2500/(35)(10) = c
A 50mL solution of 6M HCl is diluted to 1.95L. What is the
molarity of the resulting solution? - correct answer-
M1V1=M2V2
M2=(6)(0.05L)/1.95
0.30/1.95 = ~0.15 M
, A botanist has discovered a new plant and notes that it is
predominantly found in its gametophyte form. Which category
does this plant most likely belong to?
a) Bryophyte
b) Angiosperm
c) Gymnosperm
d) Seedless tracheophyte
e) Endosperm - correct answer- Bryophyte
Tracheophyte are mostly sporophyte (includes angiosperms,
seedless tracheophytes and gymnosperms)
A chemical compound X decomposes with a half life of 3 hours.
Suppose there are 20 grams of X in a container. How long will it
take for only 5 grams of X to be left in the container? - correct
answer- 20/2 = 10
10/2 = 5
therefore, 2 half lives
2 x 3 = 6 hours
A container holds 4.0L of gas at 3.5 atm and a temp of 27
degrees C. If the pressure is reduced to 0.8 atm without a
