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Alexeev081 [22]
2 years ago
14

By what method do we measure the distance to objects that are a few thousand light-years away?

Chemistry
2 answers:
Zigmanuir [339]2 years ago
8 0

Answer:

i believe the answer to your question is parallax or parsecs. im sorry im not very specific in this!

Explanation:

Wewaii [24]2 years ago
8 0
First, a dirty little secret: scientists don't actually measure astronomical distances in light years. Rather, they measure them in a unit called the Parsecs
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Hello! could anyone help me? i don't really understand. Thank you!! ​
liq [111]

I'm curious on what it is but I wish I could help

7 0
2 years ago
Pure ethylene glycol, , is added to 2.00 kg of water in the cooling system of a car. The vapor pressure of the water in the syst
spayn [35]

Answer:

1367.7 g of ethylene glycol was added to the solution

Explanation:

In order to find out the mass of glycol we added, we apply the colligative property of lowering vapor pressure: ΔP = P° . Xm

ΔP = Vapor pressure of pure solvent (P°) - Vapor pressure of solution(P')

525.8 mmHg - 451 mmHg = 451 mmHg . Xm

74.8 mmHg / 451 mmHg = Xm → 0.166 (mole fraction of solute)

Xm = Mole fraction of solute / Moles of solute + Moles of solvent

We can determine the moles of solvent → 2000 g . 1  mol/18 g = 111.1 mol

(Notice we converted the 2kg of water to g)

0.166 = Moles of solute / Moles of solute + 111.1 moles of solvent

0.166 (Moles of solute + 111.1 moles of solvent) = Moles of solute

18.4 moles = Moles of solute - 0.166 moles of solute

18.4 = 0.834 moles of solute → Moles of solute = 18.4/0.834 = 22.06 moles

Let's convert the moles to mass → 62 g/mol . 22.06 mol = 1367.7 g

6 0
3 years ago
How many moles of water are produced when 5 moles of hydrogen gas react with 2 moles of oxygen gas?
Marysya12 [62]

4 moles of water are produced

Explanation:

  • 4 moles of water are produced when 5 moles of hydrogen is reacted with 2 moles of oxygen gas
  • The balanced equation given is when 2 moles of hydrogen reacts with 1 mole of oxygen and it forms 2 moles of water.
  • The equation we have to solve is the 5 moles of hydrogen is reacting with 2 moles of oxygen gas, we can write the equation as 5H_{2} +2O_{2} -->  4H_{2} O + H_{2}
  • This is the balanced equation when 5 moles of hydrogen reacts with 2 moles of oxygen. The balanced equation means the number of hydrogen atoms and oxygen atoms on both sides would be equal in number.
4 0
3 years ago
What is the measurement for momentum?
sertanlavr [38]
The unit of momentum is the product of the units of mass and velocity.
8 0
2 years ago
Calculate the standard entropy of vaporization of ethanol at its boiling point, 352 K. The standard molar enthalpy of vaporizati
Korvikt [17]

Answer : The correct option is, (b) +115 J/mol.K

Explanation :

Formula used :

\Delta S=\frac{\Delta H_{vap}}{T_b}

where,

\Delta S = change in entropy

\Delta H_{vap} = change in enthalpy of vaporization = 40.5 kJ/mol

T_b = boiling point temperature = 352 K

Now put all the given values in the above formula, we get:

\Delta S=\frac{\Delta H_{vap}}{T_b}

\Delta S=\frac{40.5kJ/mol}{352K}

\Delta S=115J/mol.K

Therefore, the standard entropy of vaporization of ethanol at its boiling point is +115 J/mol.K

8 0
3 years ago
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