Answer:
Almost everything in our surroundings represent chemical change
Explanation:
●Rusting of iron in presence of moisture and oxygen.
●Burning of wood.
●Milk becoming curd.
●Formation of caramel from sugar by heating.
●Baking of cookies and cakes.
●Cooking any food.
●Acid-base reaction.
●Digestion of food.
Answer:
Ca²⁺ + 2 OH⁻ → Ca(OH)₂(s)
Explanation:
In chemistry, the net ionic equation is a way to write a chemical reaction whereas you write only the ions that are involved in the reaction.
When calcium chloride, CaCl₂ reacts with sodium hydroxide, NaOH to produce Ca(OH)₂ the only ions involved in the reaction are Ca²⁺ and OH⁻, thus, the balanced net ionic equation is:
<em>Ca²⁺ + 2 OH⁻ → Ca(OH)₂(s)</em>
<em>Cl⁻ and Na⁺ are not involved in the reaction and you don't have to write them.</em>
Answer:
Procedure (2)
Explanation:
Assume the dialyses come to equilibrium in the allotted times.
Procedure (1)
If you are dialyzing 5 mL of sample against 4 L of water, the concentration of NaCl will be decreased by a factor of
Procedure (2)
For the first dialysis, the factor is
After a second dialysis, the original concentration of NaCl will be reduced by a factor of
Procedure (2) is more efficient by a factor of
<h3>
Answer:</h3>
42960 years
<h3>
Explanation:</h3>
<u>We are given;</u>
- Remaining mass of C-14 in a bone is 0.3125 g
- Original mass of C-14 on the bone is 80.0 g
- Half life of C-14 is 5370 years
We are required to determine the age of the bone;
- Remaining mass = Original mass × 0.5^n , where n is the number of half lives.
Therefore;
0.3125 g = 80.0 g × 0.5^n
3.90625 × 10^-3 = 0.5^n
- Introducing logarithm on both sides;
log 3.90625 × 10^-3 = n log 0.5
Solving for n
n = log 3.90625 × 10^-3 ÷ log 0.5
= 8
- Therefore, the number of half lives is 8
- But, 1 half life is 5370 years
- Therefore;
Age of the rock = 5370 years × 8
= 42960 years
Thus, the bone is 42960 years old
