How many kilojoules are required at 0 c to melt an ice cube with a mass of 25 g

- 8.35 kJ

Solution:- It asks to calculate the heat required to melt 25 g of ice at 0 degree C. It is a phase change and the heat energy is calculated by using the formula:

where q is the heat energy, m is the mass and is the enthalpy of fusion of ice. Enthalpy of fusion of ice is 334 Joule per gram.

Let's plug in the given values in the formula:

q = 8350 J

since, 1000 = 1 kJ

So,

= 8.35 kJ

So, 8.35 kJ of heat is required to melt 25 g of ice at 0 degree C.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

it is a good conductor

explanation: