The specific latent heat of vaporisation is the energy needed to change the state from
liquid to gas at a specific temperature and pressure. It is defined as the amount of heat energy required to convert one unit mass of a substance from the liquid state to the gas state, without changing its temperature. This energy is used to overcome the intermolecular forces between the molecules in the liquid and is typically expressed in units of joules per kilogram (J/kg). The specific latent heat of vaporisation is a characteristic property of a substance and can vary depending on the substance and the conditions under which the phase change occurs.
A measuring cylinder contains water that is filled to the 50cm^3 marking. An irregularly-shaped object is placed into this water. The water is now at the 77cm^3 marking. What is the volume of the irregularly-shaped object?
To find the volume of the irregularly-shaped object, we can calculate the difference in volume between the water in the measuring cylinder before and after the object is inserted.
The initial volume of water is 50 cm^3 and the final volume is 77 cm^3.
Therefore, the volume of the irregularly-shaped object can be calculated by subtracting the initial volume from the final volume:
Volume of irregularly-shaped object = Final volume - Initial volume
= 77 cm^3 - 50 cm^3
= 27 cm^3
So, the volume of the irregularly-shaped object is 27 cm^3.
Gold has a density of 19,300kg/mᶾ. What is the mass of a gold bar, with a volume of 5 x 10⁻ᶾ mᶾ?
To find the mass of the gold bar, we can use the formula:
Mass = Density x Volume
Given that the density of gold is 19,300 kg/m³ and the volume of the gold bar is 5 x 10⁻⁶ m³, we can plug these values into the formula:
Mass = 19,300 kg/m³ x 5 x 10⁻⁶ m³
Simplifying the equation:
Mass = 96.5 kg x 10⁻⁶ m³
Converting the exponent:
Mass = 96.5 kg x 0.000001 m³
Mass = 0.0000965 kg x 1,000 grams/kg (conversion to grams)
Mass = 0.0965 grams
Therefore, the mass of the gold bar is 0.0965 grams.
thats wrong
Apologies for the mistake. Let's calculate the correct mass of the gold bar based on the given information.
Mass = Density x Volume
Given Density of gold = 19,300 kg/m³ and Volume of the gold bar = 5 x 10⁻³ m³.
Mass = 19,300 kg/m³ x (5 x 10⁻³ m³)
Mass = 19,300 kg/m³ x 0.005 m³
Mass = 96.5 kg
Therefore, the mass of the gold bar is 96.5 kg.
What happens to the temperature of a substance when it melts?
When a substance melts, its temperature remains constant until the entire substance has converted from a solid to a liquid state. This constant temperature during melting is called the melting point.
During the melting process, the energy supplied to the substance is used to overcome the forces of attraction between the molecules or atoms in the solid, and this energy is stored as potential energy. As a result, the kinetic energy of the particles does not increase, and hence, the temperature does not change.
Once the entire substance has melted, further energy input causes an increase in temperature as the molecules gain more kinetic energy in the liquid state. At this point, the substance undergoes a phase change from solid to liquid, and the temperature starts to rise again.