Answer: (a) K *[A][B]^2
(b) The answer is B
Explanation:
A)
Step1:A+B<--> C (fast)
Step2: B+C→D(slow)
Rate depends on slowest step.
so,
rate = k' [B][C] ...eqn 1
But C is intermediate.so use step 1
Since 1st step is an equilibrium,
Kc = [C] /[A][B]
so,
[C] = Kc [A][B] ...eqn 2
put eqn 2 in eqn 1
rate = k' *[B] * Kc [A][B]
= k'Kc*[A][B]^2
= K *[A][B]^2 {writing k'Kc = K}
Answer: K *[A][B]^2
B)
Answer is B
Since rate depends on slowest step.
if slowest step is:
X2Y2+Z2→X2Y2Z+Z
then only,
rate= k[X2Y2][Z2]
Answer: B
Answer:
CaF2 will not precipitate
Explanation:
Given
Volume of Ca(NO3)2
ml
Molar concentration of Ca(NO3)2 
Volume of NaF
ml
Molar concentration of NaF 
Ksp for CaF2 
CaF2 will precipitate if Q for the reaction is greater than ksp of CAF2
Moles of calcium ion

![[Ca2+] = \frac{0.01}{10 + 10} \\= \frac{0.01}{20} \\= 5 * 10^{-4}](https://tex.z-dn.net/?f=%5BCa2%2B%5D%20%3D%20%5Cfrac%7B0.01%7D%7B10%20%2B%2010%7D%20%5C%5C%3D%20%5Cfrac%7B0.01%7D%7B20%7D%20%5C%5C%3D%205%20%2A%2010%5E%7B-4%7D)
Moles of F- ion

![[F-] = \frac{0.001}{10 + 10} \\= \frac{0.001}{20} \\= 5 * 10^{-5}](https://tex.z-dn.net/?f=%5BF-%5D%20%3D%20%5Cfrac%7B0.001%7D%7B10%20%2B%2010%7D%20%5C%5C%3D%20%5Cfrac%7B0.001%7D%7B20%7D%20%5C%5C%3D%205%20%2A%2010%5E%7B-5%7D)
![Q = [Ca2+] [F-]^2\\= (5 * 10^{-4}) * (0.5* 10^-4)\\= 1.25 * 10^{-12}](https://tex.z-dn.net/?f=Q%20%3D%20%5BCa2%2B%5D%20%5BF-%5D%5E2%5C%5C%3D%20%285%20%2A%2010%5E%7B-4%7D%29%20%2A%20%280.5%2A%2010%5E-4%29%5C%5C%3D%201.25%20%2A%2010%5E%7B-12%7D)
Q is lesser than Ksp value of CaF2. Hence it will not precipitate
Answer:
Proteins and nucleic acids
Explanation:
Nitrogen compounds in animals that are no longer of use, or are in access are excreted from the animals body, and are thus called nitrogenous waste. These nitrogenous waste can be excreted in three different ways.
1. Ammonia
2. Urea
3. Uric acid
A compound is a pure substance composed of two or more different atoms chemically bonded to one another. A compound can be destroyed by chemical means. It might be broken down into simpler compounds, into its elements or a combination of the two.