All eukaryotic cells have a cell surface membrane (aka plasma membrane). It is very fragile. its role is to hold the cell together and to help control what substances can get in and out. (It is partially permeable) allowing only some substances to pass through it.
Answer: the electrostatic potential energy is -3.26 × 10⁻¹⁸ J
Explanation:
Given the data in the question;
I think the value of electrostatic potential energy of calcium sulfide CaS formed will be less(more negative) than KCl because the Ca2+ and S2- ions has more charge that is +2 and -2 respectively when compared to Kcl which has +1 and -1 charge.so it will be more negative.
radius = r + r = 100 + 184 = 284 pm = 2.84 × 10⁻¹⁰ m
we know that; k = 2.31 × 10⁻²⁸ J
q1 = 2 ( charge on Ca⁺² )
q2 = -2( charge on S⁻²)
so
Ep = k × q1q2/r
so we substitute
Ep = 2.31 × 10⁻²⁸ × (+2×-2) / 2.84 × 10⁻¹⁰
Ep = (2.31 × 10⁻²⁸ × -4) / 2.84 × 10⁻¹⁰
Ep = -9.24 × 10⁻²⁸ / 2.84 × 10⁻¹⁰
Ep = -3.26 × 10⁻¹⁸ J
Therefore, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J
Answer:
2.448 M ≅ 2.45 M.
Explanation:
Molarity (M) is the no. of moles of solute that dissolved in 1.0 L of the solution.
M = (no. of moles of solute)/(V of the solution (L).
M = (mass/molar mass) Li₂S / (V of the solution (L))
<em>∴ M of Li₂S</em> = (500.0 g/46.4 g/mol)/(4.44 L) = <em>2.448 M ≅ 2.45 M.</em>