Answer:
K⁺ (aq) + F⁻ (aq) + H⁺ (aq) + Cl⁻ (aq) → KCl (aq) + H⁺ (aq) + F⁻ (aq)
Explanation:
KF (aq) + HCl (aq) → KCl (aq) + HF (aq)
KF (aq) → K⁺ (aq) + F⁻ (aq)
HCl (aq) → H⁺ (aq) + Cl⁻ (aq)
KCl (aq) → K⁺ (aq) + Cl⁻ (aq)
HF (aq) → H⁺ (aq) + F⁻ (aq)
Answer:
0.68 V
Explanation:
For anode;
3Mg(s) ---->3Mg^2+(aq) + 6e
For cathode;
2Al^3+(aq) + 6e -----> 2Al(s)
Overall balanced reaction equation;
3Mg(s) + 2Al^3+(aq) ----> 3Mg^2+(aq) + 2Al(s)
Since
E°anode = -2.356 V
E°cathode = -1.676 V
E°cell=-1.676 -(-2.356)
E°cell= 0.68 V
Answer: It will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams
Explanation:
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Half life is represented by 
= rate constant
Given : Strontium-90 decreases in mass by one-half every 29 years , that is half life of Strontium-90 is 29 years.
As half life is independent of initial concentration, it will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams as the amount gets half.
Answer:
The type of allergy test is scratch test.
Explanation:
In a scratch test also called a skin pri c k test or puncture test, an allergy provoking substance placed on the skin is gradually scratched into the skin surface with the aid of a needle or lancet so as to detect bodily reactions to allergens. Some of the types allergens whose reactions are generally tested for include pollen, dust mites, molds and foods.
The scratch test takes about 5 to 10 minutes and it could cause slight pain and the may result in itching feeling at the location where the allergen was introduced.
Answer:
10.000 grams
Explanation:
For the first law of thermodynamics, the energy must be conserved, that means that the energy in form of heat (Q) must be equal to the sum of work (W) and internal energy(ΔU) :
Q = W + ΔU
ΔU depends on the temperature and W in the variation of pressure and volume. Q depends on the temperature, but also the mass. So, there is the same temperature, ΔU is equal for both reaction, if there is no work done, the heat must be equal for both of them. So the mass such be the same.
