Answer: The reaction produces 2.93 g H₂.
M_r: 133.34 2.016
2Al + 6HCl → 2AlCl₃ + 3H₂
Moles of AlCl₃ = 129 g AlCl₃ × (1 mol AlCl₃/133.34 g AlCl₃) = 0.9675 mol AlCl₃
Moles of H₂ = 0.9675 mol AlCl₃ × (3 mol H₂/2 mol AlCl₃) = 1.451 mol H₂
Mass of H₂ = 1.451 mol H₂ × (2.016 g H₂/1 mol H₂) = 2.93 g H₂
Explanation:
Among the choices, the unit of energy is calories. Answer in 1) is D. In 2) we are given with te mass , heat and temperature change. we just need to get the heat capacity and compare it with the following metals. The calculated heat capacity is 0.46 kJ/kg K. The answer is A. iron. In 3) we can compute the heat absorbed by the formula ΔH=mCpΔT. Cp of water is 4.18 J/g K. Answer of 3) is D. In 4) the formula used in Cp=ΔH/mΔT. Answer in 4) is A. The heat of enthalpy of fusion of ice is 80 cal/g. We convert this to J/g. Answer in 5) is B.334 J/g.
Explanation:
A property which does not bring any change in chemical composition of a substance is known as physical property.
For example, blood is more viscous than water, its pH is slightly alkaline, its temperature is about
(
) .
On the other hand, a property which changes chemical composition of a substance is known as a chemical property.
For example, precipitation, reactivity, toxicity etc are chemical property.
Sometimes, the change in color of a substance can also occur due to a chemical change.
Thus, we can conclude that following are the physical characteristics of blood.
- it is more viscous than water.
- its temperature is about
(
).
- the pH is slightly alkaline.
- it is about 8% of one’s total body weight.
Answer:
False
Explanation:
Mollusks are living organisms that can move around often, like mussels and clams, and oysters.