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2 years ago

When a metal such as copper is heated it expands. Explain

Chemistry

1 answer:

exis [7]2 years ago

6 0

Explanation:

When a metal is heated the kinetic energy in the particles increases and hence the force of attraction decreases amongst the particles - as electrons try to escape due to kinetic energy. This causes the metal to expand.

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Which type of equipment would be used to precisely measure 26.0 mL of dilute hydrochloric acid?

VikaD [51]

The type of equipment that would be used to precisely measure 26.0 mL of dilute hydrochloric acid would be C. 50 mL graduated cylinder.
D doesn't have enough mLs to measure this, and A and B have too many.

8 0

3 years ago

Read 2 more answers

Determine the molality of a solution of methanol dissolved in ethanol for which the mole fraction of methanol is 0.135. Give you

Alja [10]

<u>Answer:</u> The molality of the solution is 0.11 m

<u>Explanation:</u>

We are given:

Mole fraction of methanol = 0.135

This means that 0.135 moles of methanol is present in 1 mole of a solution

Moles of ethanol = 1 - 0.135 = 0.865 moles

To calculate the mass for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of ethanol = 0.865 moles

Molar mass of ethanol = 46 g/mol

$0.865mol=\frac{\text{Mass of ethanol}}{46g/mol}\\\\\text{Mass of ethanol}=(0.865mol\times 46g/mol}=39.79g$

To calculate the molality of solution, we use the equation:

$Molality=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

Where,

$m_{solute}$ = Given mass of solute (methanol) = 0.135 g

$M_{solute}$ = Molar mass of solute (methanol) = 32 g/mol

$W_{solvent}$ = Mass of solvent (ethanol) = 39.79 g

Putting values in above equation, we get:

$\text{Molality of methanol}=\frac{0.135\times 1000}{32\times 39.79}\\\\\text{Molality of methanol}=0.106m\approx 0.11m$

Hence, the molality of the solution is 0.11 m

6 0

3 years ago

Which type of society survives mainly by foraging for food?

Dennis_Churaev [7]

The appropriate answer is a. HUNTER-GATHERER. Hunter-gatherer societies are nomadic and they forage for edible plants, bean, fruits and nuts. They also hunt wild game for food. Early humans in the Neolithic period practiced this way of life.
Agrarian societies thrive on agriculture which they depend on for sustainable and for trade. Animals and plants are domesticated and so people can settle and build a society. Pastoral agriculture is a semi-nomadic lifestyle where the society is centered around keeping herds of grazing animals. Industrial societies focus on manufacturing and this is the backbone of the society.

6 0

2 years ago

The Ba(OH)2 dissociates as Ba+2 + 2 OH-. H2SO4 dissociates as 2 H+ + SO4 -2.

suter [353]

Answer:

The balanced equations for those dissociations are:

Ba(OH)₂(aq) → Ba²⁺(aq) + 2OH⁻ (aq)

H₂SO₄ (aq) → 2H⁺(aq) + SO₄⁻²(aq)

Explanation:

As a strong base, the barium hidroxide gives OH⁻ to the solution

As a strong acid, the sulfuric acid gives H⁺ to the solution

Ba(OH)₂, is a strong base so the dissociation is complete.

H₂SO₄ is considerd a strong acid, but only the first deprotonation is strong.

The second proton that is released, has a weak dissociation.

H₂SO₄ (aq) → H⁺(aq) + HSO₄⁻(aq)

HSO₄⁻(aq) ⇄ H⁺ (aq) + SO₄⁻² (aq) Ka

6 0

3 years ago

*click image*

nadya68 [22]

Answer:

Its be 1,2 and 4.

Explanation:

Since changing the direction won't do anything to a electric magnet.

6 0

3 years ago