<u>Answer: </u>The correct answer is Silver.
<u>Explanation:</u>
Specific heat of fusion is defined as the amount of heat which is required to raise the temperature of 1 gram of a substance to 1°C. It is generally expressed in kJ/mol
We are required to find the substance which require more heat. For that we need to know the specific heat of all the substances.
The substance which have the highest specific heat, will require more heat.
The specific heat of the given substances are:
Silver = 11.3 kJ/mol
Sulfur = 1.7175 kJ/mol
Water = 5.98 kJ/mol
Lead = 4.799 kJ/mol
The specific heat of silver is the highest and hence, will require more heat.
Hence, the correct answer is silver.
This question requires the knowledge of density.
The density of ethyl alcohol = 789 kg m⁻³
The density of water = 1000 kg m⁻³
Density = Mass / Volume
By applying ethyl alcohol,
789 kg m⁻³ = Mass / 0.9 m³
Mass = 710.1 kg
hence the mass of 0.9 m³ ethyl alcohol is 710.1 kg.
Then by applying water,
1000 kg m⁻³ = 710.1 kg / Volume
Volume = 0.7101 m³
= 0.7 m³
hence the equal water volume is 0.7 m³
The answer is a. Chemical change.
Answer:

Explanation:
Hello,
In this case, since in a dilution process the moles of the solute must remain unchanged, we use the volumes and molarities as shown below:

Clearly, the concentrated solution is 12M and the diluted solution is 0.5 M, thus, the volume of the concentrated solution we should take is:

Best regards.