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3 years ago

How do I do question number 3? And what is the answer?

Chemistry

1 answer:

shutvik [7]3 years ago

3 0

Answer:

60.02 g.

Explanation:

It is clear from the balanced equation:

Mg + 2HCl → MgCl₂ + H₂.

that 1.0 mole of Mg reacts with 2.0 moles of HCl to produce 1.0 mole of MgCl₂ and 1.0 moles of H₂.

20.0 g of Mg reacts with excess HCl. To calculate the no. of grams of HCl that reacted, we should calculate the no. of moles of Mg:

no. of moles of Mg = mass/atomic mass = (20.0 g)/(24.3 g/mol) = 0.823 mol.

From the balanced equation; every 1.0 mol of Mg reacts with 2 moles of HCl.

∴ 0.833 mol of Mg will react with (2 x 0.833 mol = 1.646 mol) of HCl.

∴ The mass of reacted HCl = no. of moles x molar mass = (1.646 mol)(36.46 g/mol) = 60.02 g.

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Which interaction occurs when light goes into an object as heat energy?

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Interaction occurs when light goes into an object as heat energy is Absorbed light.

Absorbed light makes an object dark. Absorption of light is when the light is absorbed by the object and converts it into heat energy. The objects converts the wavelength of light into the larger wavelength of heat. this makes the object warmer and produced energy. Absorption depends on the frequency of light that is transmitted. The wavelength of light defined as the distance between the the two successive troughs of the the light wave.

Therefore, Interaction occurs when light goes into an object as heat energy is Absorbed light.

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11 months ago

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Engine size is measured by how much air the cylinders displace. A 1996 Pontiac V8 has an engine size of 316.6 cubic inches. What

inna [77]

The size of this engine in cubic meters is $0.0052 m^{3}$ .

Explanation:

As it is stated that engine size can be measured depending upon the amount of air the cylinders displace, it is also stated that the engine of model Pontiac V8 has a size of 316.6 cubic inches. The problem is to convert the size of engine in cubic meters. We know that 1 inch = 0.0254 m.

Then $1 inch^{3}=(0.0254)^{3} m^{3}$

As here the size of engine is 316.6 cubic inches, then in metres it will be

$316.6 \text { inches }^{3}=316.6 \times(0.0254)^{3} \mathrm{m}^{3}=0.0052 \mathrm{m}^{3}$

Thus, the size of the engine in cubic meters will be $0.0052 m^{3}$ .

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3 years ago

7. Write the equation for the positron emission of barium-127.

ziro4ka [17]

The reaction is given by

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1 year ago

Gasoline and motor oil are chemically similar. They are both mixtures of nonpolar hydrocarbons

Softa [21]

Answer:

motor oil

Explanation:

According to Oxford dictionary, viscosity refers to ''a quantity expressing the magnitude of internal friction in a fluid, as measured by the force per unit area resisting uniform flow.''

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Motor oil is a heavier hydrocarbon than gasoline hence it is more viscous than gasoline.

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2 years ago

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John dissolves .5g of a white powder in 25g of benzene (FP 5oC) (kf benzene is 5.1) and finds the solution freezes at 3.7oC. Det

navik [9.2K]

Answer:

The compound has a molar mass of 78.4 g/mol

Explanation:

Step 1: data given

Mass of a sample = 0.5 grams

Mass of benzene = 25 grams

Freezing poing = 5 °C

Kf of benzene = 5.1 °C/m

Freezing point solution = 3.7 °C

Step 2: Calculate molality

ΔT = i*Kf*m

⇒with ΔT = the freezing point depression = 5.0 - 3.7 = 1.3 °C

⇒with i = the can't hoff factor = 1

⇒with Kf = the freezing point depression constant of benzene = 5.1 °C/m

⇒with m = the molality

1.3 = 5.1 * m

m = 1.3 / 5.1

m = 0.255 moles /kg

Step 3: Calculate moles

Molality = moles / mass benzene

0.255 molal = moles / 0.025 kg

Moles = 0.255 molal * 0.025 kg

Moles = 0.006375 moles

Step 4: Calculate molar mass of the compound

Molar mass compund = mass / moles

Molar mass compound = 0.5 grams / 0.006375 moles

Molar mass compound = 78.4 g/mol

The compound has a molar mass of 78.4 g/mol

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