Answer:
-37.63KJ
Explanation:
First, we write an equation of reaction:
H + Br ——-> HBr
Now we are told that 155g of HBr is formed. We can calculate the number of moles of HBr formed as follows:
We simply divide the mass of the HBr formed by the molar mass of HBr. The molar mass of HBr is 81g/mol
The number of moles of HBr formed is thus 81/155 = 0.52 moles
The amount of heat released is thus 0.52 * (-72) = -37.63KJ
Answer:
0.371
Explanation:
number of moles = mass / Ar
= 23.8g / 32.1 + (16.0 × 2)
= 0.37129485179 = 0.371 (3 s.f).
hope it helps :)
First step is to get the mass of water molecule in grams:
From the periodic table:
molar mass of hydrogen is 1
molar mass of oxygen is 16
molar mass of a water molecule = 2(1) + 16 = 18 gm
Now, to convert the gm into amu, all you have to do is multiply the gm you got by Avogadro's number as follows:
mass of water molecule = 18 x 6.22 x 10^23 = 1.1196 x 10^25 amu which is approximately 1 x 10^25 amu
Gallium sulphate I belive thats it dont count me on that tho
