Multiple choice

Question 1

Which of the following structures represents the conjugate acid of HPO 2- ?
A)H2PO4-.
B)H3PO4.
C) PO43-.
D) H2PO4.
E) PO42-.

Answer 1

H2PO4- (a)

Question 2

The size of the colloid particles is between ……… and …………. nm.

Answer 2

1, 500

Question 3

The solid-liquid (S/L) colloid dispersions are called

Answer 3

suspention

Question 4

The liquid-liquid (L/L) colloid dispersions are called…

Answer 4

emulsion

Question 5

Migration of the colloidal particles in an electrical field between two electrodes are called

Answer 5

electrophoresis

Question 6

Write three different effects/things that can stabilize a colloid solution!

Answer 6

1. charge
2. ion absorption
3. hydration
4. colloids

Question 7

The scattering of light by colloidal dispersion is called

Answer 7

tyndall effect

Question 8

List four methods which can be used to coagulate a colloidal solution!!

Answer 8

1. add salt
2. heating
3. electolysis
4. add sodium chloride

Question 9

What is the difference between a sol, a gel, and a xerogel? What does the “coherent” word mean?

Answer 9

sol: solution with particles
gel: coherent systmen
xerogel: no liquid (as solvent jsut solute)
coherent: molecules can meet together

Question 10

All of the following have a standard heat of formation value of zero at 25oC and 1.0 atm except:
A) He(g)
B) H2O(s)
C) O2(g)
D) H2(g) E) N2(g)

Answer 10

B) H2O(s)

Question 11

What are the “multidentate ligands” Write two examples for these ligands!

Answer 11

connect central atom ion with more bonds

Question 12

What is the “catalyst” ? Show an example!

Answer 12

make activation energy lower
eg. h2o2 -> (MnO2) H2O + O2

Question 13

Which compound is a solid in standard conditions?

Answer 13

I2, S,KMnO4, SO3, Na

Question 14

Which compound is a gas in standard conditions?

Answer 14

H2, Ar, NH3, HCl,O3,NO2

Question 15

Which compound is a liquid in standard conditions?

Answer 15

HNO3, H202, Hg, Br2

Question 16

Which one of the following substances does only exist?
a. CH6
B. NaSO4
C.KI2
D. CO3
E.Al2O2

Answer 16

e

Question 17

Which one of the following substances does only exist?
a. NaCl3
b. AL2O2
C.NH2
D.CACO3
E.K2CL

Answer 17

B

Question 18

Which one of the following substances does only exist?
A. NACL2
B.LI2O
C.NH2
D.CA2CO3
E.MGCL

Answer 18

B

Question 19

Which one of the following substances does only exist?
A. NACL2
B. AL202
C.N2H2
D.CACO3
E.KCL

Answer 19

KCL

Question 20

Which one of the following substances does only exist?
A.BABR3
B.LICL
C.HE2O
D.NK4
E.KCL2

Answer 20

B

Question 21

Which one of the following substances does only exist?
A.CH4
B.CA2SO4
C.SIO3
D.LIO4
E.NH4

Answer 21

A

Question 22

Which compound has a strong odour (smell)?
A) KMnO4
B) Br2
C) NaF
D) H2
E) C (diamond

Answer 22

Br2

Question 23

Which compound has a strong odour (smell)?
A) KMnO4
B) NH3
C) NaF
D) H2
E) C (diamond)

Answer 23

NH3

Question 24

Which one of the next materials is soluble in water? A) potassium chloride.
B) barium sulfate
C) lead sulfate.
D) iodine.
E) silver chloride.

Answer 24

a

Question 25

Which one of the next materials is NOT soluble in water? A) sodium chloride. B) ammonia. C) potassium permanganate. D) iodine. E) hydrogen chloride.

Answer 25

d

Question 26

Which of the following statements about the diamond is NOT correct ? It... A)is nonpolar. B) contains only carbon atoms. C)is built up by covalent bonds. D) is soluble in nonpolar solvents. E)is combustible.

Answer 26

D

Question 27

Which of the following statements about the sulfur’s molecule is NOT correct ? It... A) is nonpolar. B) contains 8 sulfur atom. C) built up by covalent bonds. D) ’s shape is a ring. E) contains delocalized electrons.

Answer 27

E

Question 28

Which compound gives photochemical smog with brownish color? A) NO B) SO2 C) NO2 D)CO2 E) SO3

Answer 28

C

Question 29

Which of the following statements about the oxigen is CORRECT ? It... A) is polar. B) is 78% of the air. C) is an oxidizing agent. D) has a characteristic odor. E) is a liquid under 0oC.

Answer 29

C

Question 30

goals of chromatogrphy

Answer 30

separation identification quantitative analysis