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2 years ago

3. Which of the following statements best describes friction?

Chemistry

1 answer:

mamaluj [8]2 years ago

4 0

Answer:

Explanation:

It is a force that occurs when surfaces touch each other.

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One solution has a formula C (n) H (2n) O (n) If this material weighs 288 grams, dissolves in weight 90 grams, the solution will

saw5 [17]

Explanation:

The given data is as follows.

Boiling point of water ( $T^{o}_{b}) = 100^{o}C$ = (100 + 273) K = 323 K,

Boiling point of solution ( $T_{b}) = 101.24^{o}C$ = (101.24 + 273) K = 374.24 K

Hence, change in temperature will be calculated as follows.

$\Delta T_{b} = (T_{b} - T^{o}_{b})$

= 374.24 K - 323 K

= 1.24 K

As molality is defined as the moles of solute present in kg of solvent.

Molality = $\frac{\text{weight of solute \times 1000}}{\text{molar mass of solute \times mass f solvent(g)}}$

Let molar mass of the solute is x grams.

Therefore, Molality = $\frac{\text{weight of solute \times 1000}}{\text{molar mass of solute \times mass f solvent(g)}}$

m = $\frac{288 g \times 1000}{x g \times 90}$

= $\frac{3200}{x}$

As, $\Delta T_{b} = k_{b} \times molality$

$1.24 = 0.512 ^{o}C/m \times \frac{3200}{x}$

x = $\frac{0.512 ^{o}C/m \times 3200}{1.24}$

= 1321.29 g

This means that the molar mass of the given compound is 1321.29 g.

It is given that molecular formula is $C_{n}H_{2n}O_{n}$ .

As, its empirical formula is $CH_{2}O$ and mass is 30 g/mol. Hence, calculate the value of n as follows.

n = $\frac{\text{Molecular mass}}{\text{Empirical mass}}$

= $\frac{1321.29 g}{30 g/mol}$

= 44 mol

Thus, we can conclude that the formula of given material is $C_{44}H_{88}O_{44}$ .

4 0

2 years ago

How does the reaction, A + BC ⇌ AB + C, differ from the reaction, N2 + 3H2 ⇌ 2NH3 + energy, by which ammonia is synthesized?

-BARSIC- [3]

Answer:

N₂+3H₂ ⇄2NH₃ is a thermochemical reaction whereas A+BC⇄AB is not.

A+BC⇄AB is a reaction of pure a element with a compound while N₂+3H₂ ⇄2NH₃ is a reaction between two pure elements.

Explanation:

Let A+BC⇄AB be equation i and N₂+3H₂ ⇄2NH₃ be equation ii.

The two reactions differ in that ii is a thermo-chemical reaction whereas i is not. This is because energy is included in reaction ii but not included in reaction i.

Also i is a reaction of pure a element with a compound while ii is a reaction between two pure elements. The compound is BC while the pure element is A.

6 0

3 years ago

Read 2 more answers

I need help with a questino

kipiarov [429]

Explanation:

What will the question be ?

6 0

2 years ago

Read 2 more answers

Refer to the example about diatomic gases A and B in the text to do problems 19 - 27. How many grams in 3 moles of A2?

dedylja [7]