Na2C2O4(aq) + CaCl2(aq) -----> 2NaCl(aq) + CaC2O4(s)
Here, CaC2O4(s) is a precipitate in the reaction as a result of precipitation reaction or double displacement reaction.
As we know that double displacement reaction two metal ions displaces each other from their salt solutions.
As we know that precipitation reaction is a reaction in which precipitate is formed.
The two strands must be separated like the two sides of a zipper, by breaking the weak hydrogen bonds that link the paired bases.
<u>Explanation:</u>
- A double helix structure formed by two polypeptide chains is separated like the two sides of a zipper. A zipper is formed by breaking the weak hydrogen bonds that link the paired bases. During replication, an enzyme "Helicase" travels down the DNA and splits the chain and it forms 2 separate strands.
- The two DNA strand which has the same sequence must be separated like the two sides of a zipper by breaking weak hydrogen bases. During base pair-rule, the strand are unzipped and each strands is copied.
Answer:

Explanation:
Molarity refers to a measure of concentration.
Molarity = moles of solute/Litres of solution
Molarity refers to number of moles of solute present in this solution.
In order to find a solution's molarity, use value for the number of moles of solute and the total volume of the solution expressed in liters
As molarity of 2.3 mol of Kl is dissolved in 0.5 L of water,
Molarity = 
The density of the sample is:
Density = mass / volume
Density = 9.85 / 0.675
Density = 14.6 g/cm³
If the sample has 95% gold, and 5% silver, its density should be:
0.95 x 19.3 + 0.05 x 10.5
Theoretical density = 18.9 g/cm³
The difference in theoretical and actual densities is very large, making it likely that the jeweler was not telling the truth.