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3 years ago

Which of the following reactions shows that the formation of NO2 requires

Chemistry

2 answers:

Bingel [31]3 years ago

7 0

D is the right answer

dsp733 years ago

3 0

Answer:

OPTION B:

1/2 N2(g) + O2(g) + 33.1 kJ NO2(g)

IS CORRECT

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What is the molar mass of CaCl2?

Aleks04 [339]

Answer: The molar mass of the given compound is $1.11\times 10^2 g/mol$

Explanation:

In molecular formula of $CaCl_2$ there are two chlorine atoms and one calcium atom.

The atomic mass of the calcium = 40.07 g/mol

The atomic mass of chlorine = 35.5 g/mol

Molar mass of the guven compound is :

$40.07 g/mol + 2\times 35.5 g/mol=111.07 g/mol\approx 1.11\times 10^2 g/mol$

The molar mass of the given compound is $1.11\times 10^2 g/mol$

8 0

3 years ago

Calculate the number of hydrogen atoms present in 40g of urea, (NH2)2CO

tekilochka [14]

Answer: There are $16.14 \times 10^{23}$ atoms of hydrogen are present in 40g of urea, $(NH_{2})_{2}CO$ .

Explanation:

Given: Mass of urea = 40 g

Number of moles is the mass of substance divided by its molar mass.

First, moles of urea (molar mass = 60 g/mol) are calculated as follows.

$Moles = \frac{mass}{molar mass}\\= \frac{40 g}{60 g/mol}\\= 0.67 mol$

According to the mole concept, 1 mole of every substance contains $6.022 \times 10^{23}$ atoms.

So, the number of atoms present in 0.67 moles are as follows.

$0.67 mol \times 6.022 \times 10^{23} atoms/mol\\= 4.035 \times 10^{23} atoms$

In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.

$4 \times 4.035 \times 10^{23} atoms\\= 16.14 \times 10^{23} atoms$

Thus, we can conclude that there are $16.14 \times 10^{23}$ atoms of hydrogen are present in 40g of urea, $(NH_{2})_{2}CO$ .

7 0

2 years ago

Acidic solutions have pH value less than 7 . Select one : O True O False

Marina CMI [18]

Answer:

Explanation:

The answer is true.

8 0

3 years ago

Read 2 more answers

Calculate the molality, molarity, and mole fraction of FeCl3 in a 29.5 mass % aqueous solution (d = 1.283 g/mL).

faltersainse [42]

Answer:

molality FeCl3= 2.579 molal

molarity FeCl3 = 2.333 M

mol fraction FeCl3 = 0.0444

Explanation:

Step 1: Data given

Mass % = 29.5 %

Density = 1.283 g/mL

Molar mass FeCl3 = 162.2 g/mol

Step 2: Calculate mass solution

Suppose we have 1L = 1000 mL solution

Mass solution = 1.283 g/mL * 1000 mL = 1283 grams

Step 3: Calculate mass FeCl3

Mass FeCl3 = 0.295 * 1283 grams

Mass FeCl3 = 378.485 grams

Step 4: Calculate mass of water

Mass water = 1283 - 378.485 = 904.515 grams

Step 5: Calculate moles FeCl3

Moles FeCl3 = mass FeCl3 / molar mass FeCl3

Moles FeCl3 = 378.485 grams / 162.2 g/mol

Moles FeCl3 = 2.333 moles

Step 6: Calculate moles H2O

Moles H2O = 904.515 grams / 18.02 g/mol

Moles H2O = 50.195 moles

Step 7: Mol fraction FeCl3

Mol fraction FeCl3 = 2.333 / (50.195+2.333)

Mol fraction FeCl3 = 0.0444

Step 8: Calculate molality

Molality = moles FeCl3 / mass H2O

Molality = 2.333 moles / 0.904515 kg

Molality = 2.579 molal

Step 9: Calculate molarity

Molarity = moles / volume

Molarity FeCl3 = 2.333 moles / 1 L

Molarity FeCl3 = 2.333 M

8 0

3 years ago

Vikentia [17]

Answer:

Explanation:

I think it is A because a dinosaurs are extinct so it wold be possible to find a dinosaur fossil in the coal mine.

6 0

3 years ago