16. (3 points) determine the mass of a gold bar that has a density of 19.3 g/cm3 and is 2.72 cm high by 4.21 cm long by 2.98 cm deep. you must show all of your work for credit.

The mass of gold bar is 658.516 g

Explanation:

To calculate the volume of cuboid, we use the equation:

where,

V = volume of cuboid

l = length of cuboid = 4.21 cm

b = breadth of cuboid = 2.98 cm

h = height of cuboid = 2.72 cm

Putting values in above equation, we get:

To calculate the mass of a substance, we use the equation:

Density of gold bar =

Volume of gold bar =

Putting values in equation 1, we get:

Hence, the mass of gold bar is 658.516 g

2b2t

explanation:

2b2t

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.