Which of these is always equal to the molar mass of any element?

In performing this week's bromination reaction, if you were to start with 126 mg of acetanilide (135.17 g/mol), calculate the th

Artemon [7]

Answer:

Theoretical yield of C8H8BrNO:

In moles

0.000945

In grams

0.204

Explanation:

Theoretical yield of a reaction is defined as the quantity of the product obtained from the complete conversion of a limiting reactant in a chemical reaction. Theoretical yield can be expressed as grams or moles.

Equation of reaction:

C8H9NO + Br2 --> C8H8BrNO + HBr

Since C8H9NO is the limiting reagent, 1 mole of C8H9NO reacted to form 1 mole of C8H8BrNO

Mass of C8H9NO = 129 mg

= 0.129 g.

Molar mass of C8H9NO = 135.17 g/mol.

Number of moles of C8H9NO = mass/molar mass.

= 0.129/135.17

= 0.00095 moles of C8H9NO

Since 1 mole of C8H9NO yielded 1 mole of C8H8BrNO

Therefore, 0.000954 moles of C8H8BrNO

Theoretical yield (in grams) = molar mass * number of moles

= 214.06 * 0.00095

= 0.204 of C8H8BrNO

3 0

3 years ago

A thermometer having first-order dynamics with a time constant of 1 min is placed in a temperature bath at 100oF. After the ther

sveticcg [70]

Answer:

(a) See below

(b) 103.935 °F; 102.235 °F

Explanation:

The equation relating the temperature to time is

$T = T_{0} + \Delta T\left (1 - e^{-t/\tau} \right )$

1. Calculate the thermometer readings after 0.5 min and 1 min

(a) After 0.5 min

$\begin{array}{rcl}T & = & T_{0} + \Delta T\left (1 - e^{-t/\tau} \right )\\ & = & 100 + 10\left (1 - e^{-0.5/1} \right )\\ & = & 100 + 10\left (1 - e^{-0.5} \right )\\ & = & 100 + 10 (1 - 0.6065)\\ & = & 100 + 10(0.3935)\\ & = & 100 + 3.935\\ & = & 103.935\,^{\circ}F\\\end{array}$

(b) After 1 min

$\begin{array}{rcl}T & = & T_{0} + \Delta T\left (1 - e^{-t/\tau} \right )\\ & = & 100 + 10\left (1 - e^{-1/1} \right )\\ & = & 100 + 10\left (1 - e^{-1} \right )\\ & = & 100 + 10 (1 - 0.3679)\\ & = & 100 + 10(0.6321)\\ & = & 100 + 6.321\\ & = & 106.321\,^{\circ}F\\\end{array}$

2. Calculate the thermometer reading after 2.0 min

T₀ =106.321 °F

ΔT = 100 - 106.321 °F = -6.321 °F

t = t - 1, because the cooling starts 1 min late

$\begin{array}{rcl}T & = & T_{0} + \Delta T\left (1 - e^{-(t - 1)/\tau} \right )\\ & = & 106.321 - 6.321\left (1 - e^{-(2 - 1)/1} \right )\\ & = & 106.321 - 6.321\left (1 - e^{-1} \right )\\ & = & 106.321 - 6.321 (1 - 0.3679)\\ & = & 106.321 - 6.321 (0.6321)\\ & = & 106.321 - 3.996\\ & = & 102.325\,^{\circ}F\\\end{array}$

3. Plot the temperature readings as a function of time.

The graphs are shown below.

6 0

2 years ago

A chemistry student adds a quantity of an unknown solid compound X to 5.00 L of distilled water at 15.° C . After 10 minutes of

Yuliya22 [10]

Answer:

34 g/100 mL

Explanation:

The solubility of a compound can be expressed in g/100mL, for this we must divide the mass of the compound that dissolves in the solute by the volume of the solvent.

The solvent, in this case, is water, and that mass of the solute X that dissolved is the mass that was recovered after the solvent was drained and evaporated. So the solubility of X (S) is:

S = 0.17 kg/5L

S = 170g/5000mL

S = 170g/(5*1000)mL

S = 34 g/100 mL

8 0

2 years ago

What are alveoli and what do they do?

zlopas [31]

Alveoli are tiny sacs within our lungs that allow oxygen and carbon dioxide to move between the lungs and bloodstream

6 0

3 years ago

Read 2 more answers

What do you mean by environment conservation?

BARSIC [14]

Explanation:

Environment conservation is an umbrella term that defines anything we do to protect our planet and conserve its natural resources so that every living thing can have an improved quality of life. bolivianouft and 7 more users found this answer helpful.

3 0

2 years ago