Answer:
208 g/mol and 87 g/mol
Explanation:
Number of protons = 82
Atomic mass = 126 + 82 = 208 g/mol
For ^{87}Sr
Number of neutrons = 49
Number of protons = 38
Atomic Mass = 49 + 38 = 87 g/mol
A is the answer! I’m pretty sure hopefully i helped!!
The mass of HNO3 obtained is 12.46 g from the given reaction.
The chemical reaction is :
Potassium Nitrate + Sulphuric acid ------> Potassium Bisulphate + Nitric acid.
The above reaction is basically used for the making of nitric acid.
Less than 200 degree celcius the Nitric acid if more than 200 degree celcius then it will form Potassium Sulphate.
Now,
1 mol of KNO3 reacts with1 mol of concentrated H2SO4 to give 1 mol HNO3
Molar Mass of KNO3 = 101.1 g
Molar mass of H2SO4 = 98.07 g
Mass of H2SO4 that can react with 20 g of KNO3 = (20 g* 98.07 g )/ 101.1 g
= 19.4 g
Molar mass of nitric acid= 63.01 g
Hence mass of nitric acid produced by 20 g of KNO3 = (20 g * 63.01 g ) / 101.1 g = 12.46 g
To know more about Nitric acid here :
brainly.com/question/20934865?referrer=searchResults
#SPJ1
Answer:
Fe₂O₃ is the limiting reactant.
7.57 g of MgO are formed.
Explanation:
- 3 Mg + 1 Fe₂O₃ → 2 Fe + 3 MgO
First we <u>convert the given masses of both reactants into moles</u>, using their <em>respective molar masses</em>:
- 15.6 g Mg ÷ 24.305 g/mol = 0.642 mol Mg
- 10.0 g Fe₂O₃ ÷ 159.69 g/mol = 0.0626 mol Fe₂O₃
0.0626 moles of Fe₂O₃ would react completely with (3 * 0.0626 ) 0.188 moles of Mg. As there are more Mg moles than required, Mg is the reactant in excess; thus, <em>Fe₂O₃ is the limiting reactant</em>.
We now <u>calculate how many MgO moles are produced</u>, using the <em>number of moles of the limiting reactant</em>:
- 0.0626 mol Fe₂O₃ *
= 0.188 mol MgO
Finally we <u>convert moles of MgO into grams</u>:
- 0.188 mol MgO * 40.3 g/mol = 7.57 g
The rate at which a radioactive isotope decays is measured in half-life. The term half-life is defined as the time it takes for one-half of the atoms of a radioactive material to disintegrate. Half-lives for various radioisotopes can range from a few microseconds to billions of years.
