Chemistry

Question

1. What causes water's low vapor pressure? (1 point)
dispersion forces
covalent bonding
hydrogen bonding
ionic attractions
2. Which of the following substances is the most soluble in water? (1 point)
sodium chloride
methane
bromine
carbon
3. Which of the following substances is NOT an electrolyte? (1 point)
KCl
CCl4
LiCl
Na2SO4
4. Which of the following mixture types can be filtered to remove solute? (1 point)
suspensions only
colloids only
suspensions and colloids
suspensions and solutions
5. Which of the following mixtures is NOT a colloid? (1 point)
fog
milk
paint
sugar water
6. Which of the following types of mixtures exhibit the Tyndall effect? (1 point)
suspensions and colloids
suspensions and solutions
colloids and solutions
colloids only
7. An emulsyfying agent is typically characterized by having ____. (1 point)
one polar end
one nonpolar end
two polar ends
one polar end and one nonpolar end

2 Answer

  • 1)C
    2)A
    3)B
    4)A
    5)D
    6)A
    7)D 
  • Answer 1:

    The reason is hydrogen bonding

    Explanation:

    The hydrogen bonding between liquid water molecules explains why water has an unusually low vapor pressure. We know that as the temperature increases, more molecules are released from the surface of the liquid. This increases movement above the liquid surface, increasing the pressure in the vapor stage but since water has extra bonding that is why it has low vapor pressure and comparatively high boiling point.


    Answer 2:

    Sodium chloride is more soluble in water

    Explanation:

    There is a rule in chemistry which says that like dissolve like. Since water is a polar molecule and there are partial positve and partial negative charges present between hydrogen and oxygen of its molecules. In the same way NaCl has also charged ions in it that is why water easily dissloves NaCl in it. In contrast hydrocarbons are not soluble in water because they are non polar.


    Answer 3:

    CCl4 is not an electrolyte

    Explanation:

    An electrolye is a material that causes ions to form in the solvent. Carbon tetrachloride neither dissociates into ions nor induces ion formation in the solvent. The reason is that the C − C l bond is rather strong and won't break under normal solution conditions therefore we can say that this compound is not an electrolyte when it is put in water.


    Answer 4:

    Suspensions only can be filtered to remove solute

    Explanation;

    The filtration process is generally used to separate a suspension mixture where small solid particles are suspended in liquid or air. Suspension occurs when particles are big enough to eventually settle at the bottom.Solutions are transparent, meaning that you can see through them. A suspension has bigger particle sizes and so it may look cloudy or murky. so they can be easily removed from solutions.


    Answer 5:

    Sugar water is not a colloid

    Explanation:

    A colloid is a substance microscopically dispersed evenly throughout another substance. Milk, paint and fog appear to be homogeneous mixtures and they are colloid because they have small globules of fat and protein that do not settle out after standing due to the particles but in sugar water it is not the case so we can say that sugar water is not a colloid.


    Answer 6:

    Tyndall effect occurs in suspensions and colloids

    Explanation:

    The Tyndall effect, also known as Willis–Tyndall scattering, is light scattering by particles in a colloid or in a very fine suspension. It is named after the 19th-century physicist John Tyndall. When we apply torch light on a glass of milk then the path of the light becomes visible but it is not so in case of water because in milk light is scattered by its very fine particles. This is an example of this effect


    Answer 7:

    An emulsifying agent is typically characterized by having one polar end and one non polar end

    Exploitation:

    Emulsifying substances are those that are soluble in both fat and water and enable fat to be uniformly dispersed in water as an emulsion. Those foods that consist such emulsions include butter, margarine, salad dressings, mayonnaise, and ice cream. Stabilizers maintain emulsions in a stable form. They are typically characterized by having one polar end and one nonpolar end.

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