The correct option is D.
Engineers and constructions workers have different types of footwear, which they make use of when they are in the field. Each of these foot wears has its own purpose and functions. For instance, the steel toe boots serve to protect the foot from falling falling objects and also from compression. The foot wear has a protective support in the toe and also possesses a mid sole plate to protect the foot again puncture from the sole.
15.26 miles of silver is 0.1414689408 grams
Answer:
Mass = 28.08
Explanation:
Given data:
Mass of Al₂O₃ = 21.8 g
Mass of water = 9.7 g
Mass of Al(OH)₃ = ?
Solution:
Chemical equation:
2Al(OH)₃ → Al₂O₃ + 3H₂O
Number of moles of water:
Number of moles = mass/molar mass
Number of moles = 9.7 g/ 18 g/mol
Number of moles = 0.54 mol
Number of moles of Al₂O₃:
Number of moles = mass/molar mass
Number of moles = 21.8 g/ 101.96 g/mol
Number of moles = 0.21 mol
Now we will compare the moles of Al(OH)₃ with Al₂O₃ and H₂O.
Al₂O₃ : Al(OH)₃
1 : 2
0.21 : 2×0.21 = 0.42 mol
H₂O : Al(OH)₃
3 ; 2
0.54 : 2/3×0.54 = 0.36 mol
Mass of Al(OH)₃:
Mass = number of moles × molar mass
Mass = 0.36 mol × 78 g/mol
Mass = 28.08 g
Solution;
The gas is at STP;
Where; T = 273 K , P = 1 atm
We know that 1 mole of a gas at STP occupies a volume of 22.4 liters .
V1/n1 = V2/n2
n2 = (V2/V1) n1
n2 = (2 l/22.4 l)(1 mole)
n2 = 0.0893 moles
But 1 mole of a compound has 6.022 × 10^23 molecules
Thus, number of molecules = 0.0893 moles × 6.022 ×10^23 molecules
= 5.378 × 10^22 molecules.
