All categories

3 years ago

Help on chem! Will give 30pts!

Chemistry

1 answer:

Irina-Kira [14]3 years ago

5 0

Here, substitution reaction is undergoing and the energy levels of each reaction phase is marked in graph. Its an exothermic reaction.

<h3>Explanation:</h3>

The substitution reaction is a type of reaction where a part of a molecule is substituted by another molecule to produce 2 products.

Here in the graph, in phase A we can see two molecules are coming in a reaction and they are at a particular energy level as marked. In phase B, we can see that the molecules are undergoing the substitution reaction via SN² reaction where the energy level is higher than the original energy level because of the activation energy. The difference between the energy levels is called the activation energy which is marked as D.

The final phase is the final energy levels of these 2 products where the energy level is much lower than original energy level. So the energy is lost through the reaction as heat. So the reaction is exothermic.

You might be interested in

0.102 g of an unknown(non electrolyte) compound is dissolved in enough water to make 100. mL of a solution and has an osmotic pr

Leni [432]

Answer:

680 g/m is the molar mass for the unknown, non electrolyte, compound.

Explanation:

Let's apply the formula for osmotic pressure

π = Molarity . R . T

T = T° absolute (in K)

R = Universal constant gases

π = Pressure

Molarity = mol/L

As units of R are L.atm/mol.K, we have to convert the mmHg to atm

760 mmHg is 1 atm

28.1 mmHg is (28.1 .1)/760 = 0.0369 atm

0.0369 atm = M . 0.082 L.atm/mol.K . 293K

(0.0369 atm / 0.082 mol.K/L.atm . 293K) = M

0.0015 mol/L = Molarity

This data means the mol of solute in 1L, but we have 100mL so

Molarity . volume = mol

0.0015 mol/L . 0.1L = 1.5x10⁻⁴ mole

The molar mass will be: 0.102g / 1.5x10⁻⁴ m = 680 g/m

4 0

3 years ago

Although there are different ways to approach a scientific investigation, all scientific investigations begin with some sort of

raketka [301]

Answer: hypothesis or guess

(pls mark me brainliest)

5 0

3 years ago

Read 2 more answers

Acetic acid (CH3COOH) is a weak acid that partially dissociates in water. Given the reaction CH3COOH(aq) ↔ CH3COO−(aq) + H+(aq)

likoan [24]

Answer:

The correct answer is: 1.035 x 10⁻³ M

Explanation:

The dissociation equilibrium for acetic acid (CH₃COOH) is the following:

CH₃COOH(aq) ↔ CH₃COO⁻(aq) + H⁺(aq) Kc = 1.8 x 10⁻⁵

The expression for the equilibrium constant (Kc) is the ratio of concentrations of products over reactants. The products are acetate ion (CH₃COO⁻) and hydrogen ion (H⁺) while the reactant is acetic acid (CH₃COOH):

$Kc=\frac{[CH_{3} COO^{-} ][H^{+} ]}{[CH_{3} COOH]}= 1.8 x 10^{-5}$

Given: [CH₃COOH]= 0.016 M and [CH₃COO⁻]= 0.92 M, we replace the concentrations in the equilibrium expression and we calculate [H⁺]:

$\frac{(0.016 M)[H^{+} ]}{(0.92M)}= 1.8 x 10^{-5}$

⇒[H⁺]= (1.8 x 10⁻⁵)(0.92 M)/(0.016 M)= 1.035 x 10⁻³ M

8 0

3 years ago

A mixture of gases with a pressure of 800.0 mm hg contains 60% nitrogen and 40% oxygen by volume. what is the partial pressure o

klasskru [66]

Hello!

We have the following statement data:

Data:
$P_{Total} = 800 mmHg$
$P\% N_{2} = 60\%$
$P\% O_{2} = 40\%$
$P_{partial} = ? (mmHg)$

As the percentage is the mole fraction multiplied by 100:

 $P = X_{ O_{2} }*100$

The mole fraction will be the percentage divided by 100, thus:
What is the partial pressure of oxygen in this mixture?

$X_{ O_{2} } = \frac{P}{100}$
$X_{ O_{2}} = \frac{40}{100}$
$\boxed{X_{ O_{2}} = 0.4}$

To calculate the partial pressure of the oxygen gas, it is enough to use the formula that involves the pressures (total and partial) and the fraction in quantity of matter:

In relation to $O_{2}$ :

$\frac{P O_{2} }{P_{total}} = X_O_{2}$
$\frac{P O_{2} }{800} = 0.4$
$P_O_{2} = 0.4*800$
$\boxed{\boxed{P_O_{2} = 320\:mmHg}}\end{array}}\qquad\quad\checkmark$

Answer:
b. 320.0 mm hg

7 0

3 years ago

Can someone tell me how to identify the number of significant figures?

igor_vitrenko [27]

Answer:

Non-zero digits are always significant.

Any zeros between two significant digits are significant.

A final zero or trailing zeros in the decimal portion ONLY are significant. If a number ends in zeros to the right of the decimal point, those zeros are significant.

Explanation:

1.138 has 4 significant figures, which are 1, 1, 3 and 8. The numbers after the decimal point are decimals and are significant figures.

8 0

3 years ago