Solve each problem, and express the answer in scientific notation. a.

A gas absorbs 10J of heat and is simulataneously comptessed by a constant external pressure of 0.5atm from 4L to2L in volume.Wha

Ne4ueva [31]

Answer:

B. 111 J

Explanation:

The change in internal energy is the sum of the heat absorbed and the work done on the system:

ΔU = Q + W

At constant pressure, work is:

W = P ΔV

Given:

P = 0.5 atm = 50662.5 Pa

ΔV = 4 L − 2L = 2 L = 0.002 m³

Plugging in:

W = (50662.5 Pa) (0.002 m³)

W = 101.325 J

Therefore:

ΔU = 10 J + 101.325 J

ΔU = 111.325 J

Rounded to three significant figures, the change in internal energy is 111 J.

7 0

2 years ago

Yeast converts glucose to ethanol and carbon dioxide during a process known as anaerobic fermentation. The chemical reaction is

Korolek [52]

Answer:

102g

Explanation:

To find the mass of ethanol formed, we first need to ensure that we have a balanced chemical equation. A balanced chemical equation is where the number of atoms of each element is the same on both sides of the equation (reactants and products). This is useful as only when a chemical equation is balanced, we can understand the relationship of the amount (moles) of reactant and products, or to put it simply, their relationship with one another.

In this case, the given equation is already balanced.

$\tex{C_6H_{12}O_6} \longrightarrow 2 \ C_2H_6O + 2 \ CO_2$

From the equation, the amount of ethanol produced is twice the amount of yeast present, or the same amount of carbon dioxide produced. Do note that amount refers to the number of moles here.

Mole= Mass ÷Mr

Mass= Mole ×Mr

Method 1: using the mass of glucose

Mr of glucose

= 6(12) +12(1) +6(16)

= 180

Moles of glucose reacted

= 200 ÷180

= $\frac{10}{9}$ mol

Amount of ethanol formed: moles of glucose reacted= 2: 1

Amount of ethanol

= $2(\frac{10}{9} )$

= $\frac{20}{9}$ mol

Mass of ethanol

= $\frac{20}{9} \times[2(12)+6+16]$

= $\frac{20}{9}(46)$

= 102 g (3 s.f.)

Method 2: using mass of carbon dioxide produced

Mole of carbon dioxide produced

= 97.7 ÷[12 +2(16)]

= 97.7 ÷44

= $\frac{977}{440}$ mol

Moles of ethanol: moles of carbon dioxide= 1: 1

Moles of ethanol formed= $\frac{977}{440}$ mol

Mass of ethanol formed

= $\frac{977}{440} \times[2(12)+6+16]$

= 102 g (3 s.f.)

Thus, 102 g of ethanol are formed.

Additional:

For a similar question on mass and mole ratio, do check out the following!

brainly.com/question/1685725

8 0

1 year ago

The distinctive odor of vinegar is due to acetic acid, HC₂H₃O₂, which reacts with sodium hydroxide. If a 3.45 mL sample of vineg

Vilka [71]

Answer:

Explanation:

CH₃COOH + NaOH = CH₃COONa + H₂O .

42.5 mL of .115 M of NaOH will contain .0425 x .115 moles of NaOH

= 48.875 x 10⁻⁴ moles NaOH

It will react with same number of moles of acetic acid

So number of moles of acetic acid in 3.45 mL = 48.875 x 10⁻⁴

number of moles of acetic acid in 1000 mL = 48.875 x 10⁻⁴ x 10³ / 3.45 moles

= 1.4167 moles

= 1.4167 x 60 gram

= 85 grams .

So 85 grams of acetic acid will be contained in one litre of acetic acid.

8 0

3 years ago

Fill in the coefficients that will balance the following reaction:

Burka [1]

Answer:

a0 = 2

a1= 9

a2= 6

a3= 8

Explanation:

The equation for the reaction is;

C3H7OH + O2 → CO2 + H2O

To balance the chemical equation we introduce coefficients;

Therefore the balanced chemical equation will be;

2C3H7OH + 9O2 → 6CO2 + 8H2O

Chemical equations are balanced to ensure the law of conservation of mass is obeyed, such that the mass of the reactants is equivalent to that of the products.

3 0

2 years ago

Maintenance of............of the body such as temperature level, water content, pH and blood pressure to be in balanced and stab

n200080 [17]

This is homeostasis of the body I believe.

6 0

2 years ago