Answer:

Explanation:
Hello,
In this case, for latent heat (phase change) we need to consider the enthalpy associated with the involved process, here, melting or fusion; thus, the enthalpy of fusion of copper is 13.2 kJ/mol, therefore, the heat is computed as:

Nevertheless, since the given enthalpy is per mole of copper, we need to use its atomic mass to perform the correct calculation as follows:

Which is positive as it needs to be supplied to the system.
Best regards.
Answer:
Explanation:
Molar mass of sodium hydroxide is = 100
any compund with its molar mass dissovled in 1L itres solution gives rise to 1M solution
40 g ------> 1L ---->1M
Xg ------>1L------>2M
X g= 40*1*2/1*1 =80 gram
This is true. Think about when you make pasta. The colander acts as a filter and doesn't let the past a through but allows the extra water to escape because the pasta is too big to fit.
if the scientist finds anything that does not match, they have to carry out further tests
it can guide the consumer's judgement purchase decision on too gently on what the believe the product may contain.