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3 years ago

What is the 2nd most abundant element in the earths crust

Chemistry

1 answer:

Elza [17]3 years ago

3 0

Silicon is the second most abundant element in the Earth´s crust and makes up around 27% of it.

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Nikolas, the fire extinguisher, and the skateboard have a combined mass of 50 kg. What force would the fire extinguisher have to

murzikaleks [220]

Answer:

Force used by fire extinguisher = 60 N

Explanation:

Given:

Mass of skateboard with fire extinguisher = 50 kg

Acceleration of fire extinguisher = 1.2 m/s²

Find:

Force used by fire extinguisher = ?

Computation:

⇒ Force = Mass × Acceleration

⇒ Force used by fire extinguisher = Mass of skateboard with fire extinguisher × Acceleration of fire extinguisher

⇒ Force used by fire extinguisher = 50 kg × 1.2 m/s²

⇒ Force used by fire extinguisher = 60 N

3 0

3 years ago

Read 2 more answers

A 1.42-g sample of a pure compound with formula m2so4 was dissolved in water and treated with an ex- cess of aqueous calcium chl

solong [7]

The reaction between $m_{2}SO_{4}$ with calcium chloride can be shown as- $m_{2}SO_{4}$ + $CaCl_{2}$ → $CaSO_{4}$ ↓+2mCl. The molecular weight of $CaSO_{4}$ is 136.14g. The weight of sulfate ion is 96.06g. The molecular weight of $m_{2}SO_{4}$ = (2×m + 96.06). From the reaction we can see that 1 mole of calcium chloride reacts with 1 moles $m_{2}SO_{4}$ to produce 1 mole of calcium sulfate. Now 1.36g of calcium sulfate is equivalent to 1.36/136.14=9.989× $10^{-3}$ moles of calcium sulfate.

Thus, 9.989× $10^{-3}$ moles of $m_{2}SO_{4}$ reacts in this reaction.

Let assume the atomic mass of m is x thus the molecular weight of $m_{2}SO_{4}$ is 2x+96.

So we may write 9.989× $10^{-3}$ × (2x+96) =1.42

Or, 2x + 96 = 142.146

Or, 2x = 46.146

Or, x = 23.073

Thus the atomic mass of m is 23.073. The atom (m) is sodium (Na).

8 0

3 years ago

Difference between NaOH and HCI

morpeh [17]

Compare HCl, NaOH, and NaCl: HCl is a stronger acid than water. NaCl is a weaker base than NaOH. Strong acids react with strong bases to form weaker acids and bases. ... Compare NaOH, NH3, and H2O, and NH4Cl: NaOH is a stronger base than NH3.

7 0

3 years ago

Read 2 more answers

Which of the following is true about the kinetic molecular theory?

velikii [3]

Answer: (B) Pressure is due to the collisions of the gas particles with the walls of the container.

Option B helps to explain the factor behind gas collision under high pressure.

Explanation: Kinetic molecular theory explains the behaviour and movement of gas particles when they are in motion. It states that gas particles are always in continuous motion and are perfectly elastic in nature.

Kinetic molecular theory can be explained using both Boyle's law and Charles's law.

•Few Assumptions of Kinetic Molecular Theory.

1. Gas particles are always in motion and they collide with the walls of their container.

2. The space occupied by a gas particles is negligible in comparison to the volume of the gas

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3 years ago

When 0.49 g of a molecular compound was dissolved in 20.00 g of cyclohexane, the freezing point of the solution was lowered by 3

IRISSAK [1]

Answer: The molecular mass of this compound is 131 g/mol

Explanation:

Depression in freezing point:

$\Delta T_f=i\times k_f\times \frac{w_2\times 1000}{M_2\times w_1}$