WorksheetsCHEMISTRY MIDTERM EXAM
Total questions: 31
Worksheet time: 19mins
What do you call to a long-chain molecule made from a combination of many small repeating units called as monomers?
SYNTHETIC POLYMERS: What does the word "synthetic" mean?
What is the term to describe synthetic polymer?
Thermoplastic is a plastic that can be _____
TRUE OR FALSE: Synthetic polymers are very stable. They do not corrode or decay easily.
TRUE OR FALSE: Condensation and polymerisation involves a combination of THE SAME types of monomers.
Which of the following correctly defines "elastic"?
Which of the following plastic that can be cast once because there are cross-links that are sturdy between its polymers.
What do you call the polymer that has elastic polymer like rubber?
The following are properties of Synthetic polymer, EXCEPT.
Light, hard, and strong
High density
Easy to mould or shape
Can be coloured easily
The following describes characteristic of natural rubber, EXCEPT one.
It is derived from the latex sap of rubber trees.
It can be vulcanized to improve its strength and durability.
It softens and becomes moldable when heated.
It is resistant to chemicals and temperature variations.
In the modern age, humans depend a lot on synthetic polymers and cannot live without them. This is because of the properties of synthetic polymers that are various, long-lasting, light, can be mould and shaped easily. What do you mean by the word "various"?
They are easily recyclable.
They exhibit a wide range of properties and characteristics.
They are resistant to heat and chemicals.
They are primarily derived from natural resources.
In the rubber industry, formic acid is added to latex to_____
It is a process to form cross-links between the polymer chains of rubber molecules to produce a rubber that is more elastic and better than the natural rubber.
Which of the following is the property of synthetic rubber?
Resistant to paint and moisture
TRUE OR FALSE: Synthetic rubber is a thermoplastic that is elastic and will return to its original length and shape when the applied force is removed.
Although synthetic polymers produce many adverse effects on the environment, we can still use them wisely. This is because the problem does not lie with the synthetic polymers but the irresponsible attitudes of human beings. What does the line "IRRESPONSIBLE ATTITUDES OF HUMAN BEINGS? mean?
Failure to recycle synthetic polymers
Lack of knowledge about synthetic polymers
Limited availability of synthetic polymers
Health benefits of synthetic polymers
What are chemical reactions that absorb energy?
endothermic
fast
slow
exothermic
What is the study of heat changes that accompany chemical reactions and phase changes?
energy
chemistry
work
thermochemistry
Which of the following statements describe EXOTHERMIC REACTION?
a. chemical energy is converted to heat energy
b. heat energy is transferred to the surroundings
c. temperature of surrounding decreases
d. reaction mixture and container become cold
C and D
D and A
A and B
B and C
When a piece of magnesium ribbon is dropped into a test tube containing dilute hydrochloric acid, a reaction occurs and the test tube becomes hot. This phenomenon shows heat is released by the reaction. What kind of reaction is this?
Exothermic Reaction
Physical Reaction
Chemical Reaction
Endothermic Reaction
When baking soda is added to a cup containing lime juice, a chemical reaction occurs. The cup feels cold because heat is absorbed by the reactants from the surroundings (solvent and cup). Thermometer shows a drop in temperature. What kind of heat reaction is this?
Exothermic Reaction
Chemical Reaction
Endothermic Reaction
Physical Reaction
What do you call the energy that has stored in chemical bonds in all chemical substances in which the energy content is assigned by a symbol H?
Kinetic Energy
Chemical Energy
Potential Energy
Physical Energy
Which of the following statements best describes the differences between the energy diagrams of exothermic and endothermic reactions?
In an exothermic reaction, the energy of the products is lower than the energy of the reactants, whereas in an endothermic reaction, the energy of the products is higher than the energy of the reactants.
In an exothermic reaction, the energy of the products is higher than the energy of the reactants, whereas in an endothermic reaction, the energy of the reactants is higher than the energy of the products.
Both exothermic and endothermic reactions have energy diagrams where the energy of the reactants is equal to the energy of the products.
Exothermic reactions always have a higher activation energy compared to endothermic reactions.
During a chilly camping trip, you light a hand warmer to keep your hands warm. Which type of chemical reaction is responsible for the heat produced by the hand warmer?
Endothermic reaction
Exothermic Reaction
Neutral Reaction
Endergonic Reaction
Your friend is making ice cream at home using a mixture of ice and salt to freeze the ice cream mixture. Which type of reaction is taking place between the ice and salt?
Endothermic Reaction
Neutral Reaction
Exothermic Reaction
Endergonic Reaction
A gardener uses a chemical fertilizer that heats up when mixed with water, providing warmth to the plant roots in early spring. What type of chemical reaction is this?
Exothermic Reaction
Endothermic Reaction
Neutral Reaction
Endergonic Reaction
ESSAY: 10 POINTS
According to the news report from Bernama on April 2020, the Deputy Minister of Plantation Industries and Commodities, Willie Mongin said, Malaysia being the largest latex glove producer in the world, is expecting the total report for this year to be 225 billion units with the value of more than RM20 billion. He said that this is due to Malaysia being the main producer of latex gloves to the health sector that was currently facing the critical situation following the CoVid-19 pandemic. Are latex gloves made from natural rubber or synthetic rubber?
(Write your answer at the back part of the answer sheet.)
Descriptions: This is how you will be graded.
Excellent (10): Demonstrates a thorough understanding of the controversial impact, provides a clear solution, and writes clearly and correctly.
Good (8): Shows a good understanding with minor errors, gives a relevant solution, and is mostly clear and correct.
Satisfactory (6): Shows basic understanding but with some errors, provides a solution, and has some clarity and grammar issues.
Needs Improvement (4): Shows limited understanding, lacks a clear solution, and has significant clarity and grammar issues.
(a)
Through continuous research and development, how do scientists produce synthetic polymers?
by mimicking the structure of the monomers from the natural polymers
By extracting them from natural resources
By condensing minerals and metals
By freezing liquid polymers
Which of the following statements correctly describes the differences between thermoplastic, thermoset, and elastomer materials?
Thermoplastics are rigid and do not soften with heating, while thermosets can be reshaped when heated. Elastomers are flexible and return to their original shape after deformation.
Thermoplastics can be repeatedly softened by heating and hardened by cooling. Thermosets harden irreversibly when cured, while elastomers exhibit elastic properties and return to their original shape after deformation.
Thermoplastics are highly resistant to chemicals and heat variations, whereas thermosets are derived from natural resources. Elastomers are synthetic materials used in footwear manufacturing.
Thermoplastics are liquid at room temperature and solidify upon cooling. Thermosets are lightweight metals used in aerospace applications. Elastomers are rigid materials used in construction.
What is the scientific name of Rubber Tree?
Hevea brasiliensis
Ficus elastica
Eucalyptus globulus
Picea abies
