Buffer is composed of weak acid and its conjugate base or weak base and it is conjugate acid. so The correct answer is:
0.21 M hydrofluoric acid + 0.20 M potassium Fluoride
due to the first choice contain NaOH which is strong base not weak
second choice both salts no acid or base
Third choice contain HNO₃ which is considered as strong acid
Fourth choice contain ammonia but without its conjugate acid like (NH₄Cl for example) instead it has different salt
Fifth Choice contain HF which is weak acid and KF which is its conjugate base so this is the correct one
Answer:
b. gelatin
Explanation:
a homogeneous noncrystalline consisting of large molecules or ultramicroscopic particles of one substance.
Answer:
7.2 gm or 0.0072 Kg
Explanation:
Let k be the kg of packets that are to be used.
36 X 200 mg = 1000 X k
=> k = 7.2 gm.
Answer:
HelloHelloHelloHelloanswer answeranswer answer
First we will calculate the number of moles of Iron:
, where n is the number of moles, m is the mass of iron in the reaction and M is the Atomic weight.
moles of Iron.
The same number of moles of Oxygen will take part in the reaction.
So
where 32 is the Atomical Weight of Oxygen (16 x 2).
=>
g