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3 years ago

1)

Chemistry

1 answer:

Delicious77 [7]3 years ago

6 0

Answer:

C) How much energy was added to the substance to increase molecule motion?

Explanation:

The most relevant question to ask regarding this change must take into account the physical knowledge about matter.

When matter changes from liquid state to gaseous state, a physical change called evaporation, the particles (molecules or atoms) of the pure substance will separate from each other, take up more space and move faster.

Condensation is the opposite to evaporation, thus the option A) is not the most relevant question.

The charge of the particles does not change; so the option B) is not relevant at all.

The particles should gain energy from the surroundings to increase their motion (kinetic energy) when they pass from liquid state, where they move slower, to gas state, where they move faster. Hence, the option C), How much energy was added to the substance to increase molecule motion? , is totally relevant.

Since this is an increase in the kinetic energy of the molecules, the option D) is not relevant.

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Which of the following is not an example of a pure element? Ar CO,2 O,2

KatRina [158]

O,2
hopefully that helps lol if u have any more questions like that don't be afaid to ask me

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3 years ago

When 1.2383 g of an organic iron compound containing Fe, C, H, and O was burned in O2, 2.3162 g of CO2 and 0.66285 g of H2O were

uysha [10]

Answer:

$\boxed{\text{C$_{15}$H$_{21}$FeO$_{6}$}}$

Explanation:

Let's call the unknown compound X.

1. Calculate the mass of each element in 1.23383 g of X.

(a) Mass of C

$\text{Mass of C} = \text{2.3162 g } \text{CO}_{2}\times \dfrac{\text{12.01 g C}}{\text{44.01 g }\text{CO}_{2}}= \text{0.632 07 g C}$

(b) Mass of H

$\text{Mass of H} = \text{0.66285 g }\text{H$_{2}$O}\times \dfrac{\text{2.016 g H}}{\text{18.02 g } \text{{H$_{2}$O}}} = \text{0.074 157 g H}$

(c)Mass of Fe

(i)In 0.4131g of X

$\text{Mass of Fe} = \text{0.093 33 g Fe$_{2}$O$_{3}$}\times \dfrac{\text{111.69 g Fe}}{\text{159.69 g g Fe$_{2}$O$_{3}$}} = \text{0.065 277 g Fe}$

(ii) In 1.2383 g of X

$\text{Mass of Fe} = \text{0.065277 g Fe}\times \dfrac{1.2383}{0.4131} = \text{0.195 67 g Fe}$

(d)Mass of O

Mass of O = 1.2383 - 0.632 07 - 0.074 157 - 0.195 67 = 0.336 40 g

2. Calculate the moles of each element

$\text{Moles of C = 0.63207 g C}\times\dfrac{\text{1 mol C}}{\text{12.01 g C }} = \text{0.052 629 mol C}\\\\\text{Moles of H = 0.074157 g H} \times \dfrac{\text{1 mol H}}{\text{1.008 g H}} = \text{0.073 568 mol H}\\\\\text{Moles of Fe = 0.195 67 g Fe} \times \dfrac{\text{1 mol Fe}}{\text{55.845 g Fe}} = \text{0.003 5038 mol Fe}\\\\\text{Moles of O = 0.336 40} \times \dfrac{\text{1 mol O}}{\text{16.00 g O}} = \text{0.021 025 mol O}$

3. Calculate the molar ratios

Divide all moles by the smallest number of moles.

$\text{C: } \dfrac{0.052629}{0.003 5038}= 15.021\\\\\text{H: } \dfrac{0.073568}{0.003 5038} = 20.997\\\\\text{Fe: } \dfrac{0.003 5038}{0.003 5038} = 1\\\\\text{O: } \dfrac{0.021025}{0.003 5038} = 6.0006$

4. Round the ratios to the nearest integer

C:H:O:Fe = 15:21:1:6

5. Write the empirical formula

$\text{The empirical formula is } \boxed{\textbf{C$_{15}$H$_{21}$FeO$_{6}$}}$

5 0

3 years ago

#3. How many liters are in 244 g of Krypton (Kr) gas (83.80 g/mol)?

ValentinkaMS [17]

Explanation:

100 liter because it is measured

5 0

3 years ago

Fill In the blank: Compression is the part of the medium where particles are ________.

STALIN [3.7K]

Compressed is the answer!

I hope this helps. :)

7 0

4 years ago

Determine the concentration of a solution of sodium hydroxide (NaOH) using a 0.500M Potassium Hydrogen Phthalate (KHP) standard

Svetradugi [14.3K]

Answer:

0.425M NaOH assuming the volume of KHP was 25.50mL and the volume of the NaOH solution was 30.0mL

Explanation:

The KHP reacts with NaOH as follows:

KHP + NaOH → KNaP + H₂O

Where 1 mole of KHP reacts per mole of KNaP

That means, the moles of KHP added to the NaOH solution = Moles NaOH at equivalence point. With the moles of NaOH and the volume in liters we can find the molar concentration of NaOH.

Assuming the volume added of KHP was 25.50mL and the solution of NaOH contains 30.0mL (0.0300L), the concentration of the NaOH is:

Moles KHP = Moles NaOH:

25.50mL = 0.02550L * (0.500mol / L) = 0.01275 moles KHP = Moles NaOH

Molarity NaOH:

0.01275 moles NaOH / 0.0300L =

<h3>0.425M NaOH assuming the volume of KHP was 25.50mL and the volume of the NaOH solution was 30.0mL</h3>

7 0

3 years ago