Answer:
2.2 °C/m
Explanation:
It seems the question is incomplete. However, this problem has been found in a web search, with values as follow:
" A certain substance X melts at a temperature of -9.9 °C. But if a 350 g sample of X is prepared with 31.8 g of urea (CH₄N₂O) dissolved in it, the sample is found to have a melting point of -13.2°C instead. Calculate the molal freezing point depression constant of X. Round your answer to 2 significant digits. "
So we use the formula for <em>freezing point depression</em>:
In this case, ΔTf = 13.2 - 9.9 = 3.3°C
m is the molality (moles solute/kg solvent)
- 350 g X ⇒ 350/1000 = 0.35 kg X
- 31.8 g Urea ÷ 60 g/mol = 0.53 mol Urea
Molality = 0.53 / 0.35 = 1.51 m
So now we have all the required data to <u>solve for Kf</u>:
The balanced equation for the neutralisation reaction is as follows
2NaOH + H₂SO₄ ---> Na₂SO₄ + 2H₂O
stoichiometry of NaOH to H₂SO₄ is 2:1
the number of moles of NaOH reacted - 0.126 mol/L x 0.0173 L = 0.00218 mol
if 2 mol of NaOH reacts with 1 mol of H₂SO₄
then 0.00218 mol of NaOH reacts with - 0.00218 / 2 = 0.00109 mol of H₂SO₄
molarity is the number of moles of solute in 1 L solution
therefore if 25 mL contains - 0.00109 mol
then 1000 mL contains - 0.00109 mol / 25 mL x 1000 mL = 0.0436 mol/L
therefore molarity of H₂SO₄ is 0.0436 M
<u>Explanation:</u>
<u>1. Have many moons:</u>
- Jupiter is the fifth planet from the Sun and the biggest in the Solar System and it has fifty-three moons which are confirmed and twenty-six provisional moons and totally it has seventy-nine moons and it is the only planet which has many moons.
<u>2. Have a rocky composition:</u>
- The planets which have rocky composition are also called the terrestrial planets.
- The planets which have rocky composition are listed below mercury, venus, earth, and mars and they are smaller in size.
<u>3. Revolve quickly around the Sun: </u>
- Mercury is the quickest planet, which rushes around the sun at 47.87 km/s. And it revolves around the sun quickly.
<u> 4. Rotate quickly on their axes: </u>
- The giant gas planets like Jupiter, Saturn, etc... spin more quickly on their axes than the other planets
Answer: F. Electron pair acceptor
Explanation:
A Lewis acid can be properly defined as any substance such as H+ (hygrogen ion) that can accept a pair of electron.
While a Lewis base is any substance such as (OH-) that can donate a pair of electron.
In the neutralization reaction between an acid ( H+ ) and a base (OH-). Hydrogen ion (H+ ) is the Lewis acid because it accepts an electron pair from (OH-).
Other examples of Lewis acid are; Mg2+, K+
Answer:
The physical states that are represented by each graph region are the liquid and the solid, the highest temperature is the liquid and as it freezes it becomes a solid. The particles change because when it's a liquid, it isn't that compact it's just spreading smootly but as it freezes the atoms start to stick together and become compact.
Explanation:
Hope that made sense!
