Answer:
in physics we never work with minutes only seconds.
Unit of M is also mole/L, where mole is the moles of solute and L is the volume of the solution. The latter is given: 158 mL or 0.158 L. So we need to find out the moles of NH4Br.
Moles of NH4Br = Mass of NH4Br/molar mass of NH4Br = 17.0g/(14+1*4+79.9)g/mol = 0.1736 mole.
So, the molarity of the solution = 0.1736mole/0.158L = 1.10 mole/L = 1.10 M
Answer:
No, the experimental result is different from the theoretical value.
Explanation:
Based on the given information, the mass of beaker and watchglass plus alum hydrate is 102.218 grams, and the mass of beaker and watchglass is 101.286 grams. Therefore, the mass of alum hydrate is:
= 102.218 grams - 101.286 grams
= 0.932 grams
Now the mass of anhydrous compound is,
= 102.218 grams - 101.798 grams
= 0.42 grams
Thus, the mass of water present is,
= 0.932 grams - 0.42 grams
= 0.512 grams
The mass percent of water is,
= mass of water/Total mass of hydrate * 100
= 0.512 grams / 0.932 grams * 100
= 54.93 %
Hence, the experimental result in not similar to the theoretical result.
