Balance these scientific equations:

A 3.96x10^-24 M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000-cm cuvet; a blank solution containi

viktelen [127]

Actual question from source:-

A 3.96x10-4 M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000 cm cuvette. A blank had an absorbance of 0.029. The absorbance of an unknown solution of compound A was 0.375. Find the concentration of A in the unknown.

Answer:

Molar absorptivity of compound A = $1502.53\ {Ms}^{-1}$

Explanation:

According to the Lambert's Beer law:-

$A=\epsilon l c$

Where, A is the absorbance

l is the path length

$\epsilon$ is the molar absorptivity

c is the concentration.

Given that:-

c = $3.96\times 10^{-4}\ M$

Path length = 1.000 cm

Absorbance observed = 0.624

Absorbance blank = 0.029

A = 0.624 - 0.029 = 0.595

So, applying the values in the Lambert Beer's law as shown below:-

$0.595=\epsilon\times 1.000\ cm\times 3.96\times 10^{-4}\ M$

$\epsilon=\frac{0.595}{3.96\times 10^{-4}}\ {Ms}^{-1}=1502.53\ {Ms}^{-1}$

Molar absorptivity of compound A = $1502.53\ {Ms}^{-1}$

4 0

4 years ago

Carry out electrolysis of dilute CuSO4 using copper electrodes. State the products formed at the electrodes and nature of the el

Arturiano [62]

I don’t this answer I just want points but hope someone answers this 6

7 0

3 years ago

I am a subatomic particle that is positively charged what am I?

lions [1.4K]

The right answer is Proton.

Additional Information:

There are three types of subatomic particles. They are:

Proton
Electron
Neutron

Proton is a positively charged particle,Electron is negatively charged particle and Neutron is charge less.

Hope it will be helpful to you...

6 0

3 years ago

CHEMISTRY. PLEASE HELP!!

bixtya [17]

Answer:

The answer is B on edge

Explanation:

Here are my notes on this section for anyone that needs them

Enthalpy and State Function

Bonds contain potential energy. Breaking and forming bonds involves energy. Reactants and products contain energy. Enthalpy (H) is a measure of heat and internal energy in a system.

A state function is a quantity whose change in magnitude during a process depends only on the beginning and end points the process, not the path taken between them. Enthalpy change during reaction depends only on the identity of reactants and products and their initial and finial condition

Enthalpy of Formation

enthalpy of formation (Hf) is the energy absorbed or released when a pure substance forms from elements in their standard states

Units: kJ/mol, kcal/mol

Standard state is the natural state of an element at 1 atm (atmosphere of pressure) and 25 degrees celsius. Hf for a pure element in its standard state is 0 kJ/mol.

H (hydrogen): H2(g)

N (nitrogen): N2(g)

O (oxygen): O2(g)

F (fluorine): F2(g)

Cl (chlorine): Cl2(g)

Br (bromine): Br2(l)

Hg (mercury): Hg(l)

Enthalpy of Reaction

Enthalpy of reaction (Hrxn) is energy absorbed or released during a chemical reaction

Hrxn negative: exothermic reaction

Hrxn positive: endothermic reaction

Hess's Law: Hrxn = Σ(ΔHƒ, products) − Σ(ΔHƒ, reactants)

thermochemical equation: the chemical equation that shows the state of each substance involved and the energy change involved in a reaction

Find the kJ/mol of the product and then subtract the kJ/mol of the reactants.

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Students conduct an experiment in which steel wool is burned in a closed test tube. The steel wool reacts with an amount of oxyg

Ksenya-84 [330]

The answer is 43.48g

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