The answer is c) Electrical energy
Answer: Option (D) is the correct answer.
Explanation:
- A pure substance is defined as the substance that is made up of only one type of atom or only one type of molecule.
For example,
is a molecule and it is a pure substance.
Also, substances that contain two or more different element which are chemically combined in a fixed ratio by mass are known as compounds. They are also pure substances.
A pure substance can only be separated by a chemical method and not by any physical method.
- A heterogeneous mixture is defined as the mixture which contains non-uniform composition of solute particles into the solution.
For example, mud dissolved in water.
It is not necessary that two or more substance present in a heterogeneous mixture should be of same phase.
Also, it is not necessary that combination of a liquid and a solid always results in a heterogeneous mixture.
If the solid is able to dissolve completely into the liquid then it will result in a homogeneous mixture.
- Whereas a homogeneous mixture is defined as the mixture which contains uniform distribution of solute particles into the solvent.
For example, salt dissolved in water is a homogeneous mixture.
Thus, we can conclude that the statement composition is uniform throughout a homogeneous mixture, is correct.
Answer:
Base
Explanation:
Why is Alka-Seltzer a base?
Alka-Seltzer contains sodium bicarbonate and citric acid. The sodium citrate acts as an antacid. Excess sodium bicarbonate from the Alka-Seltzer acts to neutralize base.
Answer:
K, the rate constant = 9.73 × 10^(-1)/s
Explanation:
r = K × [A]^x × [B]^y
r = Rate = 1.07 × 10^(-1)/s
K = Rate constant
A and B = Concentration in mol/dm^-3
A = 0.44M
B = 0.11M
x = Order of reaction with respect to A = 0
y = Order of reaction with respect to B = 1
Solving, we get
r/([A]^x × [B]^y) = K
K = 1.07 × 10^(-1)/s/(0.44^0 × 0.11^1)= 0.9727
K = 0.9727
Answer:
No photoelectric effect is observed for Mercury.
Explanation:
From E= hf
h= Plank's constant
f= frequency of incident light
Threshold Frequency of mercury= 435×10^3/ 6.6×10^-34 × 6.02×10^23
f= 11×10^14 Hz
The highest frequency of visible light is 7.5×10^14. This is clearly less than the threshold frequency of mercury hence no electron is emitted from the mercury surface