PLEASE HELP!!!!!!!

When 50 ml of 1.000x10^-1m pb(no3)2 solution was added to 50 ml of 1.000x10^-1m nai solution?

podryga [215]

Balanced chemical reaction: Pb(NO₃)₂ (aq) + 2NaI(aq) → 2PbI₂(s) + 2NaNO₃(aq).

V(Pb(NO₃)₂) = 50 mL ÷ 1000 mL = 0.05 L, volume of solution.

c(Pb(NO₃)₂) = 0.1 mol/L; concentration of solution.

n(Pb(NO₃)₂) = c(Pb(NO₃)₂) · V(Pb(NO₃)₂).

n(Pb(NO₃)₂) = 0.1 mol/L · 0.05 L.

n(Pb(NO₃)₂) = 0.005 mol.

n(NaI) = c(NaI) · V(NaI).

n(NaI) = 0.1 mol/L · 0.05 L.

n(NaI) = 0.005 mol; amount of substance.

From chemical reaction: n(Pb(NO₃)₂) : n(NaI) = 1 : 2.

n(Pb(NO₃)₂) = 0.005 mol ÷ 2.

n(Pb(NO₃)₂) = 0.0025 mol; number of moles Pb(NO₃)₂ used.

n(NaI) = 0.005 mol; number of moles NaI used.

The limiting reagent is Pb(NO₃)₂.

n(PbI₂) = 0.005 mol.

m(PbI₂) = n(PbI₂) · M(PbI₂).

m(PbI₂) = 0.005 mol · 461 g/mol.

m(PbI₂) = 2.305 g; the theoretical yield of PbI₂.

3 0

3 years ago

How many g of MgCO3(s) are needed to make 1.2 L of 1.5 M MgCl2(aq) solution?

maw [93]

Molar mass of MgCO3 is 84.313 g/mol
You can calculate this from data on the periodic table:
Molar mass Mg = 24.305g/mol
molar mass C = 12.011g/mol
molar mass O = 15.999g/mol mass 3 mol = 47.997g
Total = 84.313g/mol

Mass to be used in 1.2L of 1.5M solution = 84.313g * 1.2L * 1.5mol /L = 151.763g
I have not taken significant figures into account
The balanced equation you provide is not necessary in this calculation

4 0

3 years ago

Pierce conducts an experiment in which waves collide in a way that the energy increases, which means that has occurred

Vikki [24]

<h2>Answer:</h2>

It means the waves collides and constructive interference occurred.

<h3>Explanation:</h3>

If the two waves coming from the opposite direction collide with each other, there are two way of their interference.

Constructive interference: An interference which results in the increase in energy. And it is when crust of a wave comes on the crust of second wave.
Destructive interference: An interference which results in decrease in energy of the resulting wave and colliding waves cancel the result of each other.

Hence in experiment there will be constructive interference.

8 0

3 years ago

Read 2 more answers

The leaves of the rhubarb plant contain high concentrations of diprotic oxalic acid (hooccooh) and must be removed before the st

Andrei [34K]

First we have to find Ka1 and Ka2
pKa1 = - log Ka1 so Ka1 = 0.059
pKa2 = - log Ka2 so Ka2 = 6.46 x 10⁻⁵
Looking at the values of equilibrium constants we can see that the first one is really big compared to second one. so, the pH will be affected mainly by the first ionization of the acid.
Oxalic acid is H₂C₂O₄
H₂C₂O₄ ⇄ H⁺ + HC₂O₄⁻
0.0356 M 0 0
0.0356 - x x x
Ka1 = $\frac{[H^+][HC2O4^-]}{[H2C2O4]}$ = x² / 0.0356 - x
x = 0.025 M
pH = - log [H⁺] = - log (0.025) = 1.6

5 0

3 years ago

How many particles are in 1 mol of carbon? 1 mol of lithium? 1 mol of eggs? will 1 mol of each of these substances have the same

andrezito [222]

<span>One mole of a substance contains Avogadro's number of atoms/molecules/the like. This would mean that all of the items described would have approximately 6.022 * 10^23 atoms, even though their masses would differ. This would be due to the molar mass of each substance being different because of the constituent elements in the substance.</span>

8 0

3 years ago