at 65 degrees celsius, which compound has a vapor pressure of 58 kilopascals? 1. ethanoic acid2. ethanol 3. propanone 4. water

M = 81.50g, mm = m/n
n =???
PV = nRT --> n = PV/RT
n = (1.75)(4.92)/(.0821)(307)
n = 8.61/25.20 =.342
--> mm = m/n = 81.5/.342 = 238.58

Answer:

0.31%

Explanation:

For the chemical reaction:

I₂ + 2 S₂O₃²⁻ → 2 I⁻ + S₄O₆²⁻

0.043 L multiplied by 0.117 M of sodium thiosulfate gives 5.031x10⁻³ moles of S₂O₃²⁻

5.031x10⁻³ moles of S₂O₃²⁻ produces:

ClO⁻⁻ + 2 H⁺ + 2 I⁻ → I₂ + Cl⁻ + H2O

2.5156x10⁻³ moles of I₂ equates to moles of NaClO

2.5156x10⁻³ moles of NaClO times yields 0.187 g of NaClO

Thus, the mass percentage composition is:

= 0.31%

I hope this helps!

Answer:

[Cl⁻] = 0.016M

Explanation:

To begin, we analyze the reaction:

Pb(NO₃)₂ (aq) + MgCl₂ (aq) → PbCl₂ (s) ↓  +  Mg(NO₃)₂(aq)

This indicates a solubility equilibrium, resulting in the formation of lead(II) chloride precipitate. The salt can dissociate as follows:

           PbCl₂(s)  ⇄  Pb²⁺ (aq)  +  2Cl⁻ (aq)     Kps

Initial        x

React       s

Eq          x - s              s                  2s

Given that this is an equilibrium scenario, the Kps serves as the constant (Solubility product):

Kps = s. (2s)²

Kps = 4s³ = 1.7ₓ10⁻⁵

4s³ = 1.7ₓ10⁻⁵

s =  ∛(1.7ₓ10⁻⁵. 1/4)

s = 0.016 M

The quantity of carbon atoms in the pencil mark amounts to 3 x 10^17. Given that the atomic weight of carbon is 12.01 amu, it follows that 12.01 g of carbon contains 6.022 x 10^23 atoms. Thus, we can set up the equation: 12.01 g carbon/ 6.022 x 10^23 atoms (3 x 10^17 atoms) (12.01 g carbon/ 6.022 x 10^23 atoms). By canceling out the atoms, we have (3 x 10^17) (12.01 g carbon/6.022 x 10^23) and then completing the division and multiplication yields 6 x 10^-6 g of carbon. Therefore, the mass of the pencil mark is 6 x 10^-6 g.