An electron is on a -2.5 eV energy level. the electron is stuck by a 2.5 eV photon. What will most likely happen?

Lead(II) nitrate is added slowly to a solution that is 0.0800 M in Cl− ions. Calculate the concentration of Pb2+ ions (in mol /

barxatty [35]

Answer:

$[Pb^{2+}]=3.9 \times 10^{-2}M$

this is the concentration required to initiate precipitation

Explanation:

$PbCl_2$ ⇄ $Pb^{2+}+2Cl^-$

Precipitation starts when ionic product is greater than solubility product.

Ip>Ksp

Precipitation starts only when solution is supersaturated because solution become supersaturated then it does not stay in this form and precipitation starts itself only solution become saturated.

This usually happens when two solutions containing separate sources of cation and anion are mixed together and here also we are mixing lead (||)nitrate solution(source of lead(||)) into the Cl- solution.

$Ip=[Pb^{2}][2Cl^-]^2=Ksp$

$Ksp=2.4\times 10^{-4}$

lets solubility=S

$[Pb^{2+}] = S$

$[Cl^-]=2S$

$Ksp=[Pb^{2+}]\times [Cl^-]^2$

$Ksp=S \times (2S)^2$

$Ksp=4S^3$

$S=\sqrt[3]{\frac{Ksp}{4} }$

$S=3.9\times 10^{-2}$

$[Pb^{2+}]=3.9 \times 10^{-2}M$ this is the concentration required to initiate precipitation

4 0

3 years ago

What is thePercent composition of dichlorine heptoxide?

Mandarinka [93]

Answer:

The percent composition of dichlorine heptoxide is 38.76% CI and 61.24% O

8 0

3 years ago

Read 2 more answers

A chemist is studying the following reaction: NO + NO2 ⇌ N2O3. She places a mixture of NO and NO2 in a sealed container and meas

Yuri [45]

Answer:

The reaction will continue in the forward direction until all the NO or all the NO₂ is used up.

Explanation:

Le Châtelier's principle states that when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.

So, according to Le Chatelier's principle, removing the product (N₂O₃) from the system means decreasing the concentration of the products; thus, the reaction will proceed forward to produce more product to minimize the stress of removing N₂O₃ from the system.

So, the reaction will continue in the forward direction until all the NO or all the NO₂ is used up.

5 0

3 years ago

Consider this chemical reaction. What chemical is reduced? CH3OH + NAD --> CH2O + NADH

nikklg [1K]

Answer:

CH3OH and NADH

Explanation:

The given chemical reaction is an redox reaction in which reduction and oxidation take place.

In the process of oxidation: electrons are loss while in the process of reduction: electrons are gained.

In the given redox reaction: CH3OH + NAD --> CH2O + NADH

NAD is reduced to NADH as NADH gains one hydrogen electron while CH3OH (methanol) is oxidized to CH2O (methanal) by losing electrons.

So, CH3OH (methanol) and NADH are the reduced forms while NAD and CH2O (methanal) are oxidized forms.

5 0

3 years ago

2. How many moles are in 2.8 Liters of CO2 gas?

andrew-mc [135]

Answer:

0.125 moles

Explanation:

2.8 litres is equivalent to 2.8dm³

At STP,

1 mole = 22.4 dm³

x mole = 2.8 dm³

Cross multiply

22.4x = 2.8

Divide both sides by 22.4

x = 2.8/22.4

x = 0.125

4 0

2 years ago