Standard Grade Chemistry Quiz

1.

What id the chemical formula for phosphoric acid?

A.

HCl
B.

H2SO4
C.

H3PO4
D.

HNO3

Correct Answer
C. H3PO4

Explanation
Phosphoric acid is a mineral acid that is commonly used in various industries. Its chemical formula is H3PO4, which indicates that it is composed of three hydrogen atoms, one phosphorus atom, and four oxygen atoms. This formula accurately represents the composition and structure of phosphoric acid.

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2.

A salt ios a substance were the hydrogen ion of an acid has been replaced by a metal ion or an __________ ion.

Correct Answer
ammonium, Ammonium

Explanation
A salt is a substance where the hydrogen ion of an acid has been replaced by a metal ion or an ammonium ion. In this case, the correct answer is "ammonium, Ammonium" because ammonium is a specific type of ion that can replace the hydrogen ion in an acid to form a salt. The capitalization of "Ammonium" indicates that it is a proper noun and refers to the specific ion.

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3.

Which of the following facts is trueAs you move down the fractional distilation tower....

A.

The flammability increases
B.

The molecule size decreaes
C.

The products are in higher demand
D.

The products are in lower demand
E.

The boiling points decrease

Correct Answer
D. The products are in lower demand

Explanation
As you move down the fractional distillation tower, the products are in lower demand. This is because as the distillation process progresses, the molecules become more complex and heavier, resulting in products that are less desirable and have lower demand in the market.

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4.

What type of metals give a solution its colour.

Correct Answer
Transition metals, transition metals, Transition Metals

Explanation
Transition metals are known to give solutions their color. This is due to the presence of unpaired electrons in their d-orbitals, which can absorb certain wavelengths of light. When light passes through a solution containing transition metals, these electrons can absorb specific colors of light, resulting in the solution appearing colored. The repetition of "Transition metals, transition metals, Transition Metals" in the response may indicate the significance and prevalence of transition metals in determining the color of solutions.

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5.

What gas is produced in incomplete combustion?

A.

Carbon dioxide
B.

Carbon Oxide
C.

Carbon Monoxide
D.

Carbon trioxide

Correct Answer
C. Carbon Monoxide

Explanation
In incomplete combustion, not enough oxygen is available for the fuel to completely burn. This results in the production of carbon monoxide (CO) instead of carbon dioxide (CO2). Carbon monoxide is a toxic gas that is colorless, odorless, and tasteless. It is formed when carbon-containing fuels such as coal, oil, wood, or natural gas are burned in insufficient oxygen.

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6.

When does a displacement reaction occur?

Correct Answer
When a solution higher up in the electrochemical series is added to a solution of metal ions to a solution which is lower doen in the electrochemical series, when a solution higher up in the electrochemical series is added to a solution of ions to a solution which is lower down in the electrochemical series

Explanation
A displacement reaction occurs when a solution higher up in the electrochemical series is added to a solution of metal ions that are lower down in the electrochemical series. This is because metals higher up in the series have a greater tendency to lose electrons and form positive ions, while metals lower down have a lower tendency to lose electrons. Therefore, when a higher metal ion is added to a solution of lower metal ions, the higher metal ion will displace the lower metal ions from their solution, resulting in a displacement reaction. The same concept applies when a solution of higher ions is added to a solution of lower ions in the electrochemical series.

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7.

Which of the following contains a carbon to carbon double bond?

A.

Alkanes
B.

Alkenes
C.

Cycloalkanes

Correct Answer
B. Alkenes

Explanation
Alkenes contain a carbon to carbon double bond. This double bond consists of two carbon atoms sharing two pairs of electrons, resulting in a stronger and more rigid bond compared to a single bond. This double bond gives alkenes unique chemical properties, such as reactivity towards addition reactions. Alkanes, on the other hand, contain only single bonds between carbon atoms, while cycloalkanes are a type of alkane that forms a closed ring structure.

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8.

What type of reaction is electrolysis?

A.

Redox
B.

Precipitation
C.

Neutralisation

Correct Answer
A. Redox

Explanation
Electrolysis is a type of redox reaction. In a redox reaction, there is a transfer of electrons between species involved in the reaction. During electrolysis, an electric current is passed through an electrolyte solution, causing a chemical change. This involves the oxidation of one species at the anode (where electrons are lost) and the reduction of another species at the cathode (where electrons are gained). Therefore, electrolysis is considered a redox reaction.

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9.

What is a spectator ion?

Correct Answer
an ion which does not change during a chemical reaction, An ion which does not change during a chemical reaction, an ion which stays the same during a chemical reaction, An ion which stays the same during a chemical reaction

Explanation
A spectator ion is an ion that does not undergo any chemical change during a reaction. It remains in the same state before and after the reaction. Spectator ions are typically found in ionic compounds and do not participate in the overall reaction. They are present only to maintain charge balance and do not affect the outcome of the reaction. Therefore, the correct answer is "an ion which does not change during a chemical reaction" or "an ion which stays the same during a chemical reaction."

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