Chemistry questions...anyone help!?

[hollywood]

1 Gas X has a larger value than Gas Y for the
van der Waals constant “a”. This indicates
that

choices are

1. the molecules of gas X repel other X
molecules.
2. the molecules of gas X have a higher
velocity than do the molecules of gas Y.
3. the molecules of X are larger than the
molecules of Y.
4. the molecules of X have stronger inter-
molecular attractions for each other than the
molecules of Y have for each other.

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#2 Arrange the following pairs from strongest to
weakest attraction:
a) polar molecule and polar molecule
b) nonpolar molecule and nonpolar molecule
c) polar molecule and ion
d) ion and ion

choices are

1. b, c, a, d.
2. b, a, c, d.
3. d, c, b, a.
4. b, a, d, c.
5. None of these
6. a, b, c, d.
7. d, c, a, b.
8. d, a, c, b.
9. c, d, a, b
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#3 When a solution of ethanol (C2H5OH) is
formed in water, the ethanol molecules

choices are

1. form hydrogen bonds to the polar water
molecules.
2. are not attracted to the polar water
molecules.
3. form covalent bonds to the polar water
molecules.
4. are attracted to the nonpolar water
molecules.
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#4 The specific heat of water is 1.00 cal/g·◦C,
the heat of vaporization of water is 540 cal/g, and
the heat of fusion of water is 80 cal/g. How
much heat would be required to convert 10
grams of ice at 0◦C to 10 grams of water at
75◦C?

choices are

1. 6150 cal
2. 61.5 kcal
3. 1.55 kcal
4. 155 cal
5. 15.5 cal

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#5 Which of the following is true?

1. None of these statements is true.
2. Viscosity increases as the strength of in-
termolecular forces increase.
3. Viscosity increases as temperature in-
creases.
4. Vapor pressure is not affected by temper-
ature.
5. Vapor pressure increases as the strength
of intermolecular forces increases.

 

[Bob B]

You shouldn't really ask us to do your homework for you. There's no point. It only teaches you something if you do it and undertand it. Still...

1: Choice 4 is correct. Van der Waals interactions are just attractive interactions that exist between all molecules. The higher the constant, the stronger they are.

2: Choice 7 is correct. Ions exhibit the strongest electrostatic interactions of all, followed by polar molecules, followed by non-polar molecules.

3: Choice 1 is correct. Hydrogen bonds form between hydrogen and either nitrogen, oxygen or fluorine. As ethanol has a polar OH group, this can form interactions with water molecules. It isn'a covalent bond as this would take a chemical reaction, and choice 4 is definitely wrong as water molecules are polar.

4: My calculator isn't handy. What you need to do is multiply the mass by the heat of fusion. Add this to the mass multiplied by the specific heat capacity by the change in temperature of the water (i.e. 75 degrees)

I'd have to check up on 5.