Answer:
Grey precipitate implies the presence of silver ions
Yellow precipitate implies the presence of lead II ions
Explanation:
Qualitative analysis provides us a quick method of identifying ions present in a sample by chemical reactions involving simple reagents. Precipitates having a unique colour is formed. The identity of ions in the sample is deduced from the colour of precipitate obtained when particular reagents are added.
In the question, a precipitate containing silver ions upon standing turn into grey colour. Similarly, lead II ions give a yellow precipitate.
Answer:
1.75M
Explanation:
Given parameters:
Initial volume of acid, HCl = 450mL = 0.45L
Initial concentration = 3.5M
Final volume = 0.9L
Unknown:
Final concentration = ?
Solution:
This is a dilution problem in which a particular concentration is made from the stock of known concentration.
One important approach to solve this problem is to remember that the number of moles in the initial and final solution will always remain the same.
Since we know this;
Number of moles = molarity x volume;
let us find the number of moles of the initial solution;
Number of moles = 3.5 x 0.45 = 1.58moles
Now, to find the new molarity;
Molarity =
Input the parameters;
Molarity = = 1.75M
Car B has a greater momentum than A