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2 years ago

If 250 kj of energy are absorbed in the following reaction, how many moles of co2 reacted:

Chemistry

1 answer:

Hitman42 [59]2 years ago

7 0

Answer:

.54 mol

Explanation:

Using the ΔH given for the balanced reaction, convert kilojoules to moles of CO2 using the stoichiometric ratio:

250 kJ×(6 moles CO22803 kJ)=0.5351 moles CO2

The answer should have two significant figures, so round to 0.54 moles CO2.

Notice that coefficients in stoichiometric equations (indicating numbers of moles) are exact, so they do not constrain the number of significant figures.

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Amestec 140 g solutie 9% cu 260 g solutie 12%, cu 60 g apa si x g solutie 4%. Ce c procentuala are noua solutie %?

Levart [38]

Answer:

PLEASE SOMEONE SOLVE THE QUESTION OR I'M GONNA FAIL

Explanation:

Purpose and Theory: A tablet of vitamin C contains the active ingredient called ascorbic acid (HC,H,0.).

Ascorbic acid is an organic acid which is a white power and is soluble in water.

In the following microtitration lab you will be grinding up a vitamin C tablet

, and using a 0.10 g sample of the

vitamin C powder, which will be dissolved in 20-40 mL of water. This solution will be used to determine the

quantity of ascorbic acid in a commercial vitamin C tablet.

Groups

Lab 2

# of Drops 1 or Drops 2 of Drops 3

Hadia

Data & Analysis:

Complete the missing information in the following data table [24]

Trial

Volume of NaOH (drops)

0 05mL drop

(NaOH (O 0050mol/L)

Volume of NaOH (ML)

Average Volume of NaOH (ml)

T I

O 0050

00050

The balanced chemical reaction between ascorbic acid and sodium hydroxide is:

HC,H,O + NaOH NaC,H,Oye H,O,

1. Stoichiometrically calculate the mass (in grams) of ascorbic acid in the powdered sample.

3 0

3 years ago

If i have 8 L of 0.25 M solution, how many miles of MgCl2 are present

qaws [65]

Answer:

2 moles

Explanation:

The following were obtained from the question:

Molarity = 0.25 M

Volume = 8L

Mole =?

Molarity is simply defined as the mole of solute per unit litre of solution. It is represented mathematically as:

Molarity = mole of solute/Volume of solution.

With the above equation, we can easily find the number of mole of MgCl2 present in 8 L of 0.25 M MgCl2 solution as follow:

Molarity = mole of solute/Volume of solution.

0.25 = mole of MgCl2 /8

Cross multiply to express in linear form

Mole of MgCl2 = 0.25 x 8

Mole of MgCl2 = 2 moles

Therefore, 2 moles of MgCl2 are present in 8 L of 0.25 M MgCl2 solution

4 0

3 years ago

An ideal gas contained in a piston-cylinder assembly is compressed isothermally in an internally reversible process.

Tju [1.3M]

Answer:

a) $\Delta S$

b) entropy of the sistem equal to a), entropy of the universe grater than a).

Explanation:

a) The change of entropy for a reversible process:

$\delta S=\frac{\delta Q}{T}$

$\Delta S=\frac{Q}{T}$

The energy balance:

$\delta U=[tex]\delta Q- \delta W$

If the process is isothermical the U doesn't change:

$0=[tex]\delta Q- \delta W$

$\delta Q= \delta W$

$Q= W$

The work:

$W=\int_{V1}^{V2}P*dV$

If it is an ideal gas:

$P=\frac{n*R*T}{V}$

$W=\int_{V1}^{V2}\frac{n*R*T}{V}*dV$

Solving:

$W=n*R*T*ln(V2/V1)$

Replacing:

$\Delta S=\frac{n*R*T*ln(V2/V1)}{T}$

$\Delta S=n*R*ln(V2/V1)}$

Given that it's a compression: V2<V1 and ln(V2/V1)<0. So:

$\Delta S$

b) The entropy change of the sistem will be equal to the calculated in a), but the change of entropy of the universe will be 0 in a) (reversible process) and in b) has to be positive given that it is an irreversible process.

7 0

3 years ago

Problem PageQuestionSteam reforming of methane ( ) produces "synthesis gas," a mixture of carbon monoxide gas and hydrogen gas,

Serhud [2]

The question is incomplete. Her eis the complete question.

Steam reforming methane (CH4) produces "synthesis gas", a mixture of carbon monoxide gas and hydrogen gas, which is the starting point for many important industrial chemical syntheses. An industrial chemist studying this reaction fills a 125L tank with 20 mol of methane gas and 10 mol of water vapor at 38°C. He then raises the temperature, and when the mixture has come to equilibrium measures the amount of gas hydrogen to be 18 mol. Calculate the concentration equilibrium constant for the steam reforming of methane at the final temperature of the mixture. Round your answer to significant digits.

Answer: $K_{c}$ = 2. $10^{-2}$

Explanation: The reaction for steam reforming methane is:

$CH_{4} + H_{2}O$ ⇒ $CO_{} + 3H_{2}$

To calculate the concentration equilibrium constant, first calculate the molarity ( $\frac{mol}{L}$ ) of each molecule of the reaction.

At 38°C: At the initial temperature, there no products yet

Molarity of CH4:

CH4 = $\frac{20}{125}$ = 0.16M

Molarity of H20:

H2O = $\frac{10}{125}$ = 0.08M

At final temperature:

Molarity of H2:

H2 = $\frac{18}{125}$ = 0.144M

According to the chemical reaction, the combination of 1 mol of each reagents produces 1 mol of CO and 3 mols of H2, so, for the products, the ratio is 1:3.

Molarity of CO:

CO = $\frac{0.144}{3}$ = 0.048M