Answer:
30 Liters of 40% acid solution and 10 L of 60% acid solution is needed.
Explanation:
Let volume of the 40% acid solution be x.
Let volume of the 60% acid solution be y.
Volume of solution formed after mixing both solution = 40 L
x + y = 40 L..[1]
Volume of acid 40% solution = 40% of x= 0.4x
Volume of acid 60% solution = 60% of y= 0.6y
Volume of acid formed = 45% of 40 L = 
..[2]
Solving [1] and [2]
x = 30 L , y = 10 L
30 Liters of 40% acid solution and 10 L of 60% acid solution is needed.
Calculate the mass defect and nuclear binding energy of an atom ... To convert to joules per nucleon, simply divide by the number of nucleons.
Given :
A certain compound contains 4.0 g of calcium and 7.1 g of chlorine.
Its relative molecular mass is 111.
To Find :
Its empirical and molecular formulas.
Solution :
Moles of calcium , 
.
Moles of chlorine , 
.
The ratio calcium and chlorine is 1 : 2 .
So , the empirical formula is 
.
Now , molecular mass of is :
So , 
Therefore , the molecular formula is also .
Hence , this is the required solution .
Answer:
The answer is in the explanation.
Explanation:
The dissociation of a weak acid consist in the following equilibrium:
HX ⇄ H⁺ + X⁻
Where Ka is defined as:
Ka = [H⁺] [X⁻] / [HX]
A strong acid (HY) dissociates completely in water, thus:
HY → H⁺ + Y⁻
As the strong acid produces H⁺, in the equilibrium, the reaction shifts to the left -The undissociated form-, reducing the production of H⁺, allowing ignore the dissociation of the weak acid when calculating the pH.
Answer:
D
Explanation:
Recall that entropy measures the number of microstates in a substance, which is highest in gases, followed by liquids and solids. Hence, entropy increases if the products have more gaseous molecules than the reactants.
- In reaction one, chlorine gas is converted into solid NaCl, so entropy decreaes.
- In reaction two, four moles of gas are converted into two moles of gas, so entropy decreases.
- In reaction three, ice is melted to form water, which has higher entropy. Thus, entropy increases.
- In reaction four, a liquid is freezed into its solid phase, leading to a decrease in entropy.
- In reaction five, oxygen gas is converted into solid MgO, so entropy decreases.
In conclusion, the answer is D.
