Answer:
Rate constant of the reaction is
.
Explanation:
A + B + C → D + E
Let the balanced reaction be ;
aA + bB + cC → dD + eE
Expression of rate law of the reaction will be written as:
![R=k[A]^a[B]^b[C]^c](https://tex.z-dn.net/?f=R%3Dk%5BA%5D%5Ea%5BB%5D%5Eb%5BC%5D%5Ec)
Rate(R) of the reaction in trail 1 ,when :
![[A]=0.30 M,[B]=0.30 M,[C]=0.30 M](https://tex.z-dn.net/?f=%5BA%5D%3D0.30%20M%2C%5BB%5D%3D0.30%20M%2C%5BC%5D%3D0.30%20M)

...[1]
Rate(R) of the reaction in trail 2 ,when :
![[A]=0.30 M,[B]=0.30 M,[C]=0.90 M](https://tex.z-dn.net/?f=%5BA%5D%3D0.30%20M%2C%5BB%5D%3D0.30%20M%2C%5BC%5D%3D0.90%20M)

...[2]
Rate(R) of the reaction in trail 3 ,when :
![[A]=0.60 M,[B]=0.30 M,[C]=0.30 M](https://tex.z-dn.net/?f=%5BA%5D%3D0.60%20M%2C%5BB%5D%3D0.30%20M%2C%5BC%5D%3D0.30%20M)

...[3]
Rate(R) of the reaction in trail 4 ,when :
![[A]=0.60 M,[B]=0.60 M,[C]=0.30 M](https://tex.z-dn.net/?f=%5BA%5D%3D0.60%20M%2C%5BB%5D%3D0.60%20M%2C%5BC%5D%3D0.30%20M)

...[4]
By [1] ÷ [2], we get value of c ;
c = 1
By [3] ÷ [4], we get value of b ;
b = 0
By [2] ÷ [3], we get value of a ;
a = 2
Rate law of reaction is :
![R=k[A]^2[B]^0[C]^1](https://tex.z-dn.net/?f=R%3Dk%5BA%5D%5E2%5BB%5D%5E0%5BC%5D%5E1)
Rate constant of the reaction = k
![9.0\times 10^{-5} M/s=k[0.30 M]^2[0.30 M]^0[0.30 M]^1](https://tex.z-dn.net/?f=9.0%5Ctimes%2010%5E%7B-5%7D%20M%2Fs%3Dk%5B0.30%20M%5D%5E2%5B0.30%20M%5D%5E0%5B0.30%20M%5D%5E1)
![k=\frac{9.0\times 10^{-5} M/s}{[0.30 M]^2[0.30 M]^0[0.30 M]^1}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B9.0%5Ctimes%2010%5E%7B-5%7D%20M%2Fs%7D%7B%5B0.30%20M%5D%5E2%5B0.30%20M%5D%5E0%5B0.30%20M%5D%5E1%7D)

Answer:
Acid Uses
Organic acids
Citric acid As a preservative for food As a flavouring agent
Ascorbic acid (also called vitamin C) In the treatment of bone marrow and scurvy diseases
Acetic acid Added to pickles to make them sour
Explanation:
222 grams of calcium chloride is produced.
<h3><u>Explanation</u>:</h3>
The mole concept and the chemical equation are very much closely related with each other. In the chemical reaction, the compounds or elements in both sides are balanced according to the number of atoms of each side of the reaction. So from there we can easily find the amount of reactant reacts to produce desired product.
Here we can see that 2 moles of sodium chloride produces 1 mole of calcium chloride.
So, 4 moles of sodium chloride will produce 2 moles of calcium chloride.
Now, atomic weight of calcium =40.
Atomic weight of chlorine =35.5.
So,the molecular weight of calcium chloride = 
=111.
It means, 1 mole of calcium chloride weighs 111 grams.
So 2 moles of calcium chloride weighs
grams = 222 grams.
The answer to your question is A. Wrought iron because amongst its other properties, wrought iron becomes soft at red heat, and can be easily be forged and forge welded.