Total weight = 1 + 35.45 + 3 * 16 = 84.45
H = 1 / 84.45 * 100% = 1.18%
Cl = 35.45 / 84.45 * 100% = 41.98%
O = 48 / 84.45 * 100% = 56.84%
Answer:
NaCl = 58.44g/mol
Explanation:
Na = 22.99/58.44 × 100 = 39.33%
Cl = 35.45/58.44 × 100 = 60.66%
To determine the number of formula units in a sample of a compound you need to divide the number of grams by the formula mass. The formula mass of NaCl is 23 g/mol + 35.5 g/mol = 58.5 g/mol, and the number of grams of the sample is 0.14 mg * 1 g/ 1000 mg = 0.00014 g. Then the answer is 0.00014 g / 58.5 g = 2.30 * 10^ -6, which rounded to two significant figures is 2.4 * 10^ -6. So<span> the answer is 2.4 * 10^-6 or 0.0000024</span>
12.5% of strontium-90 would remain in a sample after three half-lives have passed. Half-life automatically means 50% of the original amount would remain.
Avagadros number is where 1 mol of any substance is made of 6.022 x 10²³ units. These units could be atoms making up an element of molecules making up a compound.
1 mol of Br₂ is made of 6.022 x 10²³ molecules of Br₂
the flask contains 0.100 mol
Therefore if 1 mol has 6.022 x 10²³ molecules of Br₂
then 0.1 mol has - 6.022 x 10²³ molecules/mol x 0.1 mol
therefore number of molecules - 6.022 x 10²² Br₂ molecules ₂
