Answer:
K = [HI]² / [H₂] [I₂]
Explanation:
To write the expression of equilibrium constant, K, it is important that we know how to obtain the equilibrium constant.
The equilibrium constant, K for a given reaction is simply defined as the ratio of the concentration of the products raised to their coefficient to the concentration of the reactants raised to their coefficient. Thus, the equilibrium constant is written as follow:
K = [Product] / [Reactant]
Now, we shall determine the equilibrium constant for the reaction given in the question above. This can be obtained as illustrated below:
H₂(g) + I₂(g) —> 2HI (g)
K = [HI]² / [H₂] [I₂]
Answer:
2.1x10⁹ years
Explanation:
U-238 is a radioactive substance, which decays in radioactive particles. It means that this substance will lose mass, and will form another compound, the Pb-206.
The time need for a compound loses half of its mass is called half-life, and knowing the initial mass (mi) and the final mass (m) the number of half-lives passed (n) can be found by:
m = mi/2ⁿ
The mass of Pb-206 will be the mass that was lost by U-238, so it will be mi - m. Thus, the mass ration can be expressed as:
(mi-m)/m = 0.337/1
mi - m = 0.337m
mi = 1.337m
Substituing mi in the expression of half-life:
m = 1.337m/2ⁿ
2ⁿ = 1.337m/m
2ⁿ = 1.337
ln(2ⁿ) = ln(1.337)
n*ln(2) = ln(1.337)
n = ln(1.337)/ln2
n = 0.4190
The time passed (t), or the age of the sample, is the half-life time multiplied by n:
t = 4.5x10⁹ * 0.4190
t = 1.88x10⁹ ≅ 2.1x10⁹ years
The answer is D, coal is a nonrenewable resource.
Answer:
The heat lost by the water 
3.8 KJ
The heat gain by ice 
= 228.76 J
The heat required to melt the ice 
= 3340 J
Explanation:
Mass of ice cube 
= 10 gm
Initial temperature of ice cube 
= 0 °c
Mass of water 
= 100 gm
Initial temperature of water 
= 20 °c
Final temperature of mixture 
= 10.93 °c
(a). Total heat lost by the water 
( - )
⇒ 100 × 4.184 (20 - 10.93)
⇒ 3.8 KJ
This is the heat lost by the water.
(b). Heat gained by the ice cube = 
⇒ = 10 × 2.093 × ( 10.93 - 0)
⇒ = 228.76 J
This is the heat gain by ice.
(C). Heat required to melt the ice = × Latent Heat
⇒ = 10 × 334
⇒ = 3340 J
This is the heat required to melt the ice.
Answer:
False
Explanation:
Many abused drugs are prescription drugs.
