Answer:
102g of crystals
Explanation:
When the Cr(NO₃)₃⋅9H₂O is dissolved in water at 15°C, the maximum mass that water will dissolve in the equilibrium is 208 g per 100g of water. When you heat the water, this mass will increases.
In this problem, at 35°C the water dissolves 310g in 100g of water, as in the equilibrium at 15°C the maximum mass is 208g, the mass of crystals that will form is:
310g - 208g = <em>102g of crystals</em>
<em>-Crystals are the Cr(NO₃)₃⋅9H₂O that is not dissolved-.</em>
I hope it helps!
Answer:
mass HF = 150.05 g
Explanation:
- SiO2(s) + 4HF(g) → SiF4(g) + 2H2O(l)
⇒ Q = (ΔH°rxn * mHF) / (mol HF * MwHF )
∴ MwHF = 20.0063 g/mol
∴ mol HF = 4 mol
∴ ΔH°rxn = - 184 KJ
∴ Q = 345 KJ
mass HF ( mHF ):
⇒ mHF = ( Q * mol HF * MwHF ) / ΔH°rxn
⇒ mHF = ( 345 KJ * 4mol HF * 20.0063 g/mol ) / 184 KJ
⇒ mHF = 150.05 g HF
Answer: I believe C is your best answer
Explanation: The earth revolves around the sun in an elongated circle. Every year is one full “circle.” Due to the earth also having a tilt on its axis, one “side” of the earth is usually closer to the sun. So In the first quarter of the earth’s travel around the sun, it’ll be winter, then the next quarter, spring, followed by Summer halfway through and then Autumn/fall. Such can be compared to how the seasons each usually fill in about a quarter of your calendar. That was explained a bit confusing but I hope I helped, good luck!
Answer:
look at the graph
Explanation:
We know that as temperature increases, solubility increases.So, when there is a rise in temperature, as more solute become dissolved, the saturation point will be lifted and more amount of solute will be needed to reach saturation.
Here, when the temperature was 20oC, 38 g of salt was needed for saturation. As the temperature is increased by 15oC, at 35oC more amount of salt was needed to reach saturation(45g). So a 15oC rise in temperature caused a 7 g rise in the amount of salt needed for saturation. So, if temperature is increased additionally through 10oC, an approximate 4.5 g of salt will be needed more to reach the saturation. That is at 45oC, the amount of salt at saturation will be approximately 49.5 g.
So, the temperature and solubility as well as temperature and amount of salt at saturation are linearly related(directly proportional)
Answer:
Explanation:
It is easier if you convert the kelvin temperature into Celsius degrees:
- ºC = T - 273.15 = 150 - 273.15 = -123.15ºC
Now, you know that that is a very cold temperature. Thus, may be the oxygen is not gas any more but it changed to liquid . . . or solid?
You must search for the boiling point and melting (freezing) point of oxygen in tables or the internet. At standard pressure (about 1 atm) they are:
- Melting point: −218.79 °C,
- Boiling point: −182.962 °C
That means that:
- below -218.79ºC oxygen is solid (not our case).
- between -218.79ºC and -182.962ºC oxygen is liquid (not our case)
- over -182.962ºC oxygen is a gas. This is our case, because -123.15ºC is a higher temperature than -182.962ºC.
Hence, <em>the state of matter of oxygen at 150K</em>, and standard pressure, is gas.
