Answer:
12.7g of Cu
Explanation:
First let us generate a balanced equation for the reaction. This is illustrated below:
Zn + CuSO4 —> ZnSO4 + Cu
Molar Mass of Cu = 63.5g/mol
Molar Mass of CuSO4 = 63.5 + 32 + (16x4) = 63.5 + 32 + 64 = 159.5g/mol
From the equation,
159.5g of CuSO4 produced 63.5g of Cu.
Therefore, 31.9g of CuSO4 will produce = (31.9 x 63.5) / 159.5 = 12.7g of Cu
The question is incomplete:
Complete question is
The most efficient way to determine whether a reaction is an exothermic chemical
reaction is to use —
A) an oxygen probe
B) a temperature probe
C) a pressure probe
D) a pH probe
...............................................................................................................
Answer:
Reaction is said to be exothermic in nature, if heat is evolved from the system. The resultant product formed is more stable. Since, during exothermic reaction, heat is given out be the system, temperature of system will increase. Hence, temperature is the probe to determine exothermic reaction.
Thus, correct answer is option B) a temperature probe
II think thihe answer is to be part of the acid to be honest
All those compounds are ionic.
Then they dissociate into ions when they are in water.
I will write the dissociation equations. The charges of the ions is indicated inside parenthesis.
KI -> K (+) + I (-) => two ions
K2SO4 -> 2 k(+) + SO4 (2-) -> three ions
NaCl -> Na(+) + Cl(-) => two ions
KBr -> K(+) + Br(-)
As you se every molecule of the compound K2SO4 dissociates into three ions, while the other compounds dissociate into two ions. Given that the decrase in the freezong point of water is proportional to the number of particles dissolved, the K2SO4 will lower the freezing point the most.
Answer: option B. K2SO4
I pretty sure the answer is a