Science Experiment Quiz

What is the total volume of carbon dioxide produced in the first 3.5 minutes?

• 47 cm³

• 35 cm³

• 60 cm³

• 20 cm³

Answer explanation

The total volume of carbon dioxide produced in the first 3.5 minutes is calculated based on the rate of production. The correct answer is 47 cm³, as it aligns with the given data and calculations.

Using the tangent, what is the rate of reaction at 3.5 minutes in cm³ per minute?

• 13.4 cm³ per minute

• 10 cm³ per minute

• 15 cm³ per minute

• 8 cm³ per minute

Answer explanation

To find the rate of reaction at 3.5 minutes, we use the slope of the tangent line at that point on the graph. The calculated slope is 13.4 cm³ per minute, making it the correct choice.

Which change would make the rate of reaction slower?

• Using the same acid at a higher temperature

• Using acid of a lower concentration

• Using a larger flask

• Adding a catalyst

Answer explanation

Using acid of a lower concentration decreases the number of reactive particles, leading to fewer collisions and a slower reaction rate. Higher temperature, larger flasks, and catalysts would generally increase the reaction rate.

Which property makes argon gas suitable for joining metal pieces with a very hot flame?

• Argon has a low density

• Argon has a low melting point

• Argon is colourless

• Argon is unreactive

Answer explanation

Argon is unreactive, which means it does not react with metals or other materials during welding. This property allows it to provide an inert atmosphere, preventing oxidation and ensuring a clean joint when joining metal pieces with a hot flame.

What is the name of the substance with the formula AgNO₃?

• Silver Nitrogen Oxide

• Silver Nitrate

• Silver Oxide

• Silver Chloride

Answer explanation

The formula AgNO₃ represents Silver Nitrate, which consists of silver (Ag), nitrogen (N), and three oxygen (O) atoms. The other options do not match this composition.

What is the electronic configuration of the Na⁺ ion?

• 1

• 2.8

• 2.8.1

• 2.8.2

Answer explanation

The Na⁺ ion has lost one electron from its neutral sodium atom, which has the electronic configuration of 2.8. Thus, the correct configuration for Na⁺ is 2.8, indicating it has 2 electrons in the first shell and 8 in the second.

Why can a solution of sodium carbonate conduct electricity, but solid sodium carbonate cannot?

• Ions in solution can move freely.

• Solid sodium carbonate is a good conductor.

• Electrons in solid can move freely.

• Solution has no ions.

Answer explanation

A solution of sodium carbonate conducts electricity because the ions are free to move. In solid sodium carbonate, the ions are fixed in place and cannot move, preventing electrical conductivity.

Calculate the percentage by mass of sodium in sodium carbonate, Na₂CO₃.

• 23.4%

• 43.4%

• 33.4%

• 53.4%

Answer explanation

To find the percentage by mass of sodium in Na₂CO₃, calculate the molar mass: Na (23 g/mol) x 2 + C (12 g/mol) + O (16 g/mol x 3) = 106 g/mol. Sodium's contribution is 46 g. Thus, (46/106) x 100 = 43.4%.

What is the mass of titanium oxide used in the reaction?

• 100.00 tonnes

• 45.26 tonnes

• 60.00 tonnes

• 75.40 tonnes

Answer explanation

The mass of titanium oxide used in the reaction is 100.00 tonnes, which is the correct choice as it aligns with the requirements of the reaction and is the only option that meets the specified mass.

What is the percentage yield of titanium in the process?

• 75.4%

• 60.0%

• 45.3%

• 100.0%

Answer explanation

The percentage yield of titanium is calculated by comparing the actual yield to the theoretical yield. In this case, the correct percentage yield is 75.4%, indicating a successful extraction process.