Given that 1 mole contains 6.02x10^23 molecules, 3.0x10^23 is just around half a mole. Then we check the number of moles for each choice:
A. This is approximately half a mole, since the molar mass of Br2 is 159.8 g/mol.
B. He has a molar mass around 4 g/mol, so this is 1 mole.
C. H2 has a molar mass of 2.02 g/mol, so this is 2 moles.
D. Li has a molar mass of around 6.97 g/mol, so this is around 2 moles.
Therefore the only choice that fits is A. 80 g of Br2.
Explanation:
I am not understanding your question
Answer: negative , from , to , exothermic
Explanation:
An endothermic reaction is a type of chemical reaction in which energy is absorbed from the surrounding. The temperature of the surrounding decreases.
An Exothermic reaction is a type of chemical reaction in which energy is released into the surrounding. The temperature of the surrounding increases.
Endothermic reactions are those in which heat is absorbed by the system from the surroundings and exothermic reactions are those in which heat is released by the system to the surroundings.
for Endothermic reaction is positive and
As on dissolution of salt, the temperature of water increases, the heat has been released from system into surroundings and thus
is negative.
Answer:
a,d,e
Explanation:
its a,d, and e because clean air keeps us alive and other organisms need it to stay alive