<span>The following is the role of NaCl and EDTA in DNA isolation, hope it helps:
NaCl provides Na+ ions that will block negative charge from phosphates on DNA.
Negatively charged phosphates on DNA cause molecules to repel each other. The Na+ ions will form an ionic bond with the negatively charged phosphates on the DNA, neutralizing the negative charges and allowing the DNA molecules to come together.</span>
For moles to grams would be the mole which is 7.9*10^-1 times the molar mass of argon
ΔH° = -769.2 kJ is required.
<u>Explanation:</u>
Given equations are:
Pb(s) + PbO₂(s) + 2 H₂SO₄(l) → 2 PbSO₄(s) + 2H₂O(l); ΔH° = –509.2 kJ ------1
SO₃(g) + H₂O(l) → H₂SO₄(l); ΔH° = –130. kJ ----2
From the above 2 equations, by adding or subtracting or multiplying or dividing the required amount to get the final equation by means of Hess's law.
Multiplying eq. 2 by 2 we will get,
2 SO₃(g) + 2 H₂O(l) → 2 H₂SO₄(l) ; ΔH° = -260 kJ ----3
Adding it to eq. 1 we will get,
Pb(s) + PbO₂(s) + 2 H₂SO₄(l) → 2 PbSO₄(s) + 2H₂O(l); ΔH° = –509.2 kJ ------1
2 H₂SO₄ and 2 H₂O gets cancelled since they are on opposite sides, and the ΔH° values are added to get the ΔH° value of the required equation as,
Pb(s) + PbO₂(s) + 2 SO₃(g) → 2 PbSO₄(s)
ΔH° = -509.2 - 260 = -769.2 kJ
Wax molecules have most of their weak van der waals interactions and other hydrophobic interactions decrease and thus most of them are broken between these lipid substances, allowing for the increased molecular movement of these substances. As there are fewer interactions between similar compounds.
