Answer:
5.85 grams of NaCl should be added to 250 grams of water to make a 0.40 m solution.
Explanation:
Mass of NaCl =x
Molar mass of NaCl = 58.5 g/mol
Molality of the solution = 0.40 m
Mass of the solvent = 250 g = 0.250 kg (1g = 0.001 kg)
5.85 grams of NaCl should be added to 250 grams of water to make a 0.40 m solution.
2.1653 g
Explanation:
The molar mass of Rubidium is;
85.468 g/mol
Therefore the moles of Rubidium that reacted with oxygen is;
1.98 / 85.468
= 0.0232 moles
If every two moles of Rubidium reacts with one mole of oxygen then the amount of oxygen consumed in the chemical reaction is;
0.5 * 0.0232
= 0.0116 moles
The molar mass of an oxygen atom is 16 g/mole. Then the amount of O in grams consumed is;
0.0116 * 16
=0.1853 g
The final weight of the Rubidium II Oxide is;
1.98 + 0.1853
= 2.1653 g
They are called the noble gasesbecause they are very unreactive. The highest occupied energy levels (outermost shells) of their atoms are full: helium atoms have two electrons in their outer energy level. atoms of the other noble gases have eight electrons in their outer energy level.
Explanation:
<h3>HOPE IT WILL HELP YOU TO SOLVE YOUR PROBLEM.</h3>
