Answer:
0.7561 g.
Explanation:
- The hydrogen than can be prepared from Al according to the balanced equation:
<em>2Al + 6HCl → 2AlCl₃ + 3H₂,</em>
It is clear that 2.0 moles of Al react with 6.0 mole of HCl to produce 2.0 moles of AlCl₃ and 3.0 mole of H₂.
- Firstly, we need to calculate the no. of moles of (6.8 g) of Al:
no. of moles of Al = mass/atomic mass = (6.8 g)/(26.98 g/mol) = 0.252 mol.
<em>Using cross multiplication:</em>
2.0 mol of Al produce → 3.0 mol of H₂, from stichiometry.
0.252 mol of Al need to react → ??? mol of H₂.
∴ the no. of moles of H₂ that can be prepared from 6.80 g of aluminum = (3.0 mol)(0.252 mol)/(2.0 mol) = 0.3781 mol.
- Now, we can get the mass of H₂ that can be prepared from 6.80 g of aluminum:
mass of H₂ = (no. of moles)(molar mass) = (0.3781 mol)(2.0 g/mol) = 0.7561 g.
Answer:
B.brief in water vapor, fixed in liquid water, and nonexistent in ice crystals.
Explanation:
Water's States: Gas, Liquid, and Solid
In liquid water, hydrogen bonds are constantly formed and broken as the water molecules slide past each other. The breaking of these bonds is caused by the motion (kinetic energy) of the water molecules due to the heat contained in the system.
Hope It Helps You
Density is found by dividing mass over volume:
d=M/V. In this problem, we know the density, and the mass. Solve the general equation for volume, then enter the values from the problem and evaluate:
d=m/v [multiply v to both sides, then divide d from both sides]
v=m/d
v=83.8g/(2.33g/cm³)
v=35.965 cm³
v=36.0 cm³ to three significant figures (since your given information only has 3 sig figs)
When cohesive force is stronger than the adhesive force: concave up meniscus, water forms droplets on surface
Answer : The crown is not made of pure (100%) gold.
Explanation :
Formula used :
where,
= apparent weight of the crown in water = 4.50 N
= actual weight = 5.00 N
= density of water = 
= density of crown = ?
Now put all the given values in the above formula, we get:
Density of crown < Density of gold
Thus, the crown is not made of pure (100%) gold.
