Answer:
2.318032g
Explanation:
-The electrolysis equation of water is written as below:
-The mole ratio of Water to the hydrogen formed is 1:1, therefore 2.3 moles of hydrogen gas is produced.
-Hydrogen's molar mass is 1.00784 grams:
Hence, 2.318032 grams of hydrogen is produced.
Reaction Rate is the rate at which a substance undergoes a chemical change.
The answers are
The age of the oldest stars
How fast distant galaxies are moving away from us
Patterns of background radiation.
Explanation:
The Astronomers calculate the age of the universe by looking for oldest stars, and by measuring the rate of expansion of the universe and back to big bang.
The Astronomers used the techniques like the age of oldest stars, how fast the distant galaxies are moving away from us, patterns of background radiation and along with the Big Bang as reference point, they estimate that the universe may be approximately 12 billion years old.
Answer:
333.7g of antifreeze
Explanation:
Freezing point depression in a solvent (In this case, water) occurs by the addition of a solute. The law is:
ΔT = Kf × m × i
Where:
ΔT is change in temperature (0°C - -20°C = 20°C)
Kf is freezing point depression constant (1.86°C / m)
m is molality of solution (moles solute / 0.5 kg solvent -500g water-)
i is Van't Hoff factor (1, assuming antifreeze is ethylene glycol -C₂H₄(OH)₂)
Replacing:
20°C = 1.86°C / m × moles solute / 0.5 kg solvent × 1
5.376 = moles solute
As molar mass of ethylene glycol is 62.07g/mol:
5.376 moles × (62.07g / 1mol) = <em>333.7g of antifreeze</em>.
From the calculation as shpwn in the procedure below, the equilibrium constant of the substance is 6.9 * 10^-15.
<h3>What is equilibrium constant?</h3>
The equilibrium constant for the solubility of aa solid in solution is called the solubility product Ksp. The Ksp shows the extent to which a solid is dissolved in solution.
Given that;
Fe(OH)2 ⇄Fe^2+ + 2(OH)^-
Ksp = s(2s)^2
We have s as 1.2 x 10^-5 M
So
Ksp = 4s^3
Ksp = 4( 1.2 x 10^-5 )^3
Ksp = 6.9 * 10^-15
Learn more about Ksp:brainly.com/question/27132799
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