Percent composition by mass is calculated (mass of element within compound)/(mass of compound)*100. The lower the total molar mass of the compound, the greater the percent composition of sulfur. In this case, MgS would be that compound, since Mg has the lowest molar mass of the four elements bonded to S.
For the very last question you would first divide 8,900 by 12 and the number you get will be the answer. You should get 741.66
Molarity = (Mass/ molar mass) x (1/ volume of solution in Litres)
Mass = Molarity x molar mass x volume of solution in Litres
Molarity of Tris = 100 mM = 0.1 M
volume of Tris sol. = 100 mL = 0.1 L
molar mass of Tris = 121.1 g/mol
Hence,
mass of Tris = Molarity of Tris x molar mass ofTris x volume of Tris solution
= 0.1 M x 121.1 g/mol x 0.1 L
= 1.211 g
mass of Tris = 1.211 g
Answer:
a. Be and Mg
Explanation:
Be (beryllium) and Mg (magnesium) are both found in the alkaline earth metals family (group 2) on the periodic table. Elements in the same family or group have similar properties,
Ca and Br are in groups 2 and 17
Cl and Ar are in groups 17 and 18
Na and P are in groups 1 and 15
Answer:
- <u><em>1.12 liters</em></u>
Explanation:
<u>Calculating number of moles</u>
- Molar mass of O₂ = 32 g
- n = Given weight / Molar mass
- n = 1.6/32
- n = 0.05 moles
<u>At STP</u>
- One mole of O₂ occupies 22.4 L
- Therefore, 0.05 moles will occupy :
- 22.4 L x 0.05 = <u><em>1.12 L</em></u>
