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3 years ago

Calculate the molality of a solution formed by adding 6.30 g NH4CL to 15.7 g of water

Chemistry

1 answer:

babymother [125]3 years ago

6 0

Answer:

Molality = 7.5 mol/kg

Explanation:

Given data:

Mass of NH₄Cl = 6.30 g

Mass of water = 15.7 g (15.7/1000 =0.016 kg)

Molality = ?

Solution:

Formula of molality:

Molality = Moles of solute / mass of solvent in gram

Now we will first calculate the number of moles of solute( NH₄Cl )

Number of moles = mass/ molar mass

Molar mass of NH₄Cl = 53.491 g/mol

Number of moles = 6.30 g/ 53.491 g/mol

Number of moles = 0.12 mol

Now we will calculate the molality.

Molality = Moles of solute / mass of solvent in gram

Molality = 0.12 mol / 0.016 kg

Molality = 7.5 m

or (m=mol/kg)

Molality = 7.5 mol/kg

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Methylpropane (complete and condensed structural formulas)

Tcecarenko [31]

Answer:

Here's what I get

Explanation:

1. Complete structural formula

Methylpropane consists of a chain of three carbons with another carbon atom attached to the middle carbon. Enough H atoms are added to give each C atom a total of four bonds.

The complete structural formula is shown below (There is a C atom at each intersection).

2. Condensed structural formula

A condensed structural formula is designed to be typed on one line.

The molecule has three CH₃ groups attached to a single carbon atom, so the condensed structural formula is

(CH₃)₃CH

The formula is also often written CH₃CH(CH₃)CH₃ and as (CH₃)₂CHCH₃.

5 0

3 years ago

What is a characteristic of asexual reproduction?

Zepler [3.9K]

Answer:

Sexual reproduction

6 0

3 years ago

Read 2 more answers

A sample of propane(c3h8)has 3.84x10^24 H atoms.

deff fn [24]

Answer:

A) 14. 25 × 10²³ Carbon atoms

B) 34.72 grams

Explanation:

1 molecule of Propane has 3 atoms of Carbon and 8 atoms of Hydrogen.

The sample has 3.84 × 10²⁴ H atoms.

If 8 atoms of Hydrogrn are present in 1 molecule of propane.

3.84 × 10²⁴ H atoms are present in

$\mathfrak{ \frac{3.8 }{8} \times 10 ^{24}}$

= 4.75 × 10²³ molecules of Propane.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

No. of Carbon atoms in 1 molecule of propane = 3

=> C atoms in 4.75× 10²³ molecules of Propane = 3 × 4.75 × 10²³

= 14.25 × 10²³ 

________________________________________

Gram Molecular Mass of Propane(C3H8)

= 3 × 12 + 8 × 1

= 36 + 8

= 44 g

1 mole of propane weighs 44g and has 6.02× 10²³ molecules of Propane.

=> 6.02 × 10²³ molecules of Propane weigh = 44 g

=> 4. 75 × 10²³ molecules of Propane weigh =

$\mathsf{ \frac{44 }{6.02 \times {10}^{23} } \times 4.75 \times {10}^{23} }$

$\mathsf{ = \frac{44 }{6.02 \times \cancel{{10}^{23} }} \times 4.75 \times \cancel{ {10}^{23}} }$

$\mathsf{ = \frac{44 }{6.02 } \times 4.75 }$

= 34.72 g

8 0

2 years ago

1. Plants that perform photosynthesis convert sun (solar) energy to food energy.

Alinara [238K]

Answer:

true

Explanation:

one reason is because plants need sunlight and water because it is their source of food

3 0

3 years ago

A chemist determined by measurements that 0.050 moles of aluminum participated in a chemical reaction. Calculate the mass of alu

Law Incorporation [45]

Answer:

13.5 g

Explanation:

This question is solved easily if we remember that the number of moles is obtained by dividing the mass into the atomic weight or molar mass depending if we are referring to elements or molecules.

Therefore, the mass of aluminum in the reaction will the 0.050 mol Al times the atomic weight of aluminum.

number of moles = n = mass of Al / Atomic Weight Al

⇒ mass Al = n x Atomic Weight Al = 0.050 mol x 27 g mol⁻¹

= 13.5 g

We have three significant figures in 0.050 and therefore we should have three significant figures in our answer.

8 0

3 years ago