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Multiple choice chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

Metal cation ionic solids dissolve in solution exothermically.This is best explained by which of the following?

  1. The hydrogen bonding in the water break apart, releasing large amounts of energy that are used to force a breaking of the ionic structure.

  2. The free floating electrons in the metal cations provide a large measure of electricity when the ionic solid is broken down in the water.

  3. The breaking of the ionic structure, which releases bond energy causing the solution to be exothermic.

  4. The attraction of the cations and anions to the dipoles in water, resulting in a release of energy.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Metal cationic  solids dissolve in solution exothermally due the free floating of electrons in the metal cations provide a large measure of electricity when the ionic solid is broken done in the water.

Hence option B is correct.
Multiple choice chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

The reaction between sodium and water can be made less vigorous by:

  1. adding a little alcohol

  2. amalgamatic sodium

  3. adding a little acitic acid

  4. lowering the temperature
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If we add sodium to water it floats on the water and reacts very vigorously, rushing around and on the surface producing hydrogen gas and sodium hydroxide. Hence to reduce its vigorousness, it is amalgamated with mercury by making sodium as amalgamating sodium. 

Option (B) is correct.

Multiple choice chemistry man made materials plastic waste thermocol ways to reduce non degradable garbage

Electrical wires have a coating of an insulated material. The material generally used is :

  1. sulphur

  2. graphite

  3. PVC

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

PVC is an abbreviated form of polyvinyl chloride. The electrical characteristics of PVC such as electrical insulating properties or dielectric constant are excellent and hence, are used as insulating materials.

Multiple choice chemistry man made materials plastic waste thermocol ways to reduce non degradable garbage

The plastics which soften upon being heated but regains all its original properties on cooling are known as:

  1. thermoplastics

  2. thermosetting plastics

  3. thermoelastic

  4. cellulose
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The plastics which soften upon being heated but remain an original properties on cooking are known thermoplastics.

Example: Polythelene, PVC, Acrylic, Nylon and Teflon

Multiple choice chemistry man made materials plastic waste thermocol ways to reduce non degradable garbage

Plastic can be used for:

  1. polythene bags

  2. food packaging

  3. electrical appliances

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Plastic in today's world plays a very important role in day to day life. They are most commonly used as polythene bags (carry bags). Also they are used in food industry for packaging as wrappers, tetra packs for milk etc. Plastics can be good thermal insulator. Hence, can be used to coat all the electrical appliances.

Multiple choice chemistry man made materials plastic waste thermocol ways to reduce non degradable garbage

______ are the substances are capable of molding and casting into various shapes and sizes.

  1. Thermosettig plastic

  2. Thermoplastic

  3. Polyamide

  4. Polyesters
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Thermoplastics are materials which become soft on heating and gets hardened when cooled. This process of heating and cooling can be performed several times on thermoplastic without significant change in its characteristics. Due to these properties, thermoplastics can be molded and cast into various shapes and sizes