Phase Diagrams

Calculate the mass percent composition of sulfur in Al2(SO4)3.

% of S = mass of S / total mass × 100 % = 96.18u/342.14u × 100 % =28.11 %

How many atoms of oxygen are contained in 47.6 g of Al2(CO3)3? The molar mass of Al2(CO3)3 is 233.99 g/mol.

1.10⋅1024 https://socratic.org/questions/how-many-atoms-of-oxygen-are-contained-in-47-6-g-of-al-2-co-3-3-the-molar-mass-o-1

The (unlabeled) phase diagram for an unknown substance is shown below. What is the approximate normal boiling point for this substance?

170 K

Which one of the following contains 40% carbon by mass? CH3CO2H C2H2 CO2 CH4

CH3CO2H

Open the phase diagram for CO2 given in the introduction again. Use the phase diagram for CO2 in the interactive activity and determine which of the following statements are correct. CO2 is a gas under normal conditions of temperature and pressure. All three phases of CO2 exist simultaneously at the triple point. When the pressure is 4 atm and the temperature is more than −56.7∘C, CO2 exists as a solid. When the pressure is 1 atm, there is no temperature at which the liquid phase of CO2 exists. Movement across boundary line BO corresponds to a phase change. CO2 forms a supercritical fluid at temperatures less than 31∘C.

CO2 is a gas under normal conditions of temperature and pressure. All three phases of CO2 exist simultaneously at the triple point. When the pressure is 1 atm, there is no temperature at which the liquid phase of CO2 exists. Movement across boundary line BO corresponds to a phase change.

Using the phase diagram below, predict the physical state of the substance represented at 1.00 atm and 398 K.

Gas

Points A to G are located on the phase diagram of water. Which of the following statements are correct regarding navigation from one point to another across the phase diagram? To move from point G to point B, you must increase the temperature. Moving from point A to point C, the temperature increases. To move from point C to point D, you must decrease only the pressure. At point E, the temperature is less than 0∘C To move from point D to point F, you must decrease both the temperature and the pressure. To move from the point G to point F, you must increase both the temperature and the pressure.

Moving from point A to point C, the temperature increases. To move from point C to point D, you must decrease only the pressure. At point E, the temperature is less than 0∘C To move from the point G to point F, you must increase both the temperature and the pressure.

The table below gives the temperature and pressure of the triple point for five different substances. Substance Temperature (K) Pressure (atm) Xe 161 0.80 UF6 337 1.50 I2 387 0.12 CO 68 0.15 On heating from low temperature at 1 atm of pressure which substance is most likely to sublime rather than melt?

Sublimation is process of transfer of substance from solid to vapor state through heating and raising the temperature. Melting is a process of transfer of substance from solid to liquid state though heating. The initial condition for each substance is at 1 atm and low temperature. The substance which sublimes should be lower than the triple point. So the triple point must be greater than the initial state. Therefore the correct option is UF6

In the phase diagram of water, the red line labeled A represents a change in pressure at constant temperature. Which statement is NOT true about that change? The change goes from gas to solid to liquid. The state changes involve all three states. The change does not pass through the triple point. The change goes from gas to solid.

The change goes from gas to solid.

Butane (C4H10) is the liquid fuel in lighters. How many grams of carbon are present within a lighter containing 7.25 mL of butane? (The density of liquid butane is 0.601 g/mL.)

The mass percent of carbon in butane is 82.7%. The given volume of butane (7.25 mL) multiplied by its density (in g/mL) yields the mass of butane, which is 4.36 g. The mass of carbon in the lighter is then calculated by multiplying the mass of butane by the mass percent ratio of carbon in butane (4.36 g×0.827=3.60 g).

List the elements in the compound CF2Br2 in order of decreasing mass percent composition.

The molar mass of CF2B2 = 209. 82 F2 = 38 molar mass Br2 = 159.81 molar mass Percenatge of Carbon = 12/ 209.82 = 0.057 = 5.7 % Percenatge of Fluorine = 38/209.82 = 0.182 = 18.2 % Percenatge of Bromine = 159.81/209.82 = 0.761 = 76.1% Decreasing order is Br> F > C.

Determine the mass of potassium in 36.6 g of KI.

The molar mass of KI =39.10g/mol+126.9/mol=166.0g/mol 36.6gKI×(39.10gK/166.0gKI)=8.62gK

If you begin with a sample of carbon dioxide at −60.0∘C and 0.50 atm and warm it to 30.0∘C and 0.50 atm, then there will be no phase transition in the sample.

True

Determine the mass of oxygen in a 7.2 g sample of Al2(SO4)3.

Your answer 4.04 g was either rounded differently or used a different number of significant figures than required for this part. The mass percent of oxygen in aluminum sulfate (molar mass = 342.132 g/mol) is 56.1%, which is calculated as follows: mass percent of O in Al2(SO4)3=(12×15.998 g)/mol342.132 g/mol The mass of oxygen in 7.2 g of aluminum sulfate is then calculated by multiplying the mass percent ratio of oxygen by the sample mass (7.2 g×0.561=4.0 g).

A phosphorus compound that contains 13.07% phosphorus by mass has the formula X3P2. Identify the element X.

formula = X3P2 molarmass of P = 31 g/mol for 2P = 62 g that means , 62 g = 13.07% remaining 86.93% = 62*86.93/13.07 = 412.37 g so that, 3 X = 412.37 x = 412.37/3 = 137.46 g/mol from the periodictable Ba = molarmass = 137.3 g/mol so that, the X = Ba(Barium)

A sample of the substance in this phase diagram is initially at 185 ∘C and 950 mmHg. Which phase transition occurs when the temperature is changed to 130 ∘C at constant pressure?

liquid to solid At 185 ∘C and 950 mmHg, this substance is a liquid. When the temperature is decreased, the freezing curve is crossed and the substance becomes a solid.

Determine the mass percent (to the hundredths place) of Na in sodium bicarbonate (NaHCO3).

molar mass of NaHCO_3 = (22.99+1.008+12.01+16(3)) = 84.008 molar mass of Na = 16*3 = 22.989769 22.989769/84.008= 27.36

If ice is heated at a constant pressure of 0.00512 atm, it will _______ If ice is heated at a constant pressure of 1 atm, it will _______ If the pressure of water vapor is increased at a constant temperature of 100 degrees Celsius, it will _________ If the pressure of water vapor is increased at a constant temperature of -50 degrees Celsius, it will _________

sablime melt condense deposit

What state transition or transistions occur in carbon dioxide if you begin with a sample of carbon dioxide at −60.0 ∘C at 5.0 atm and warm the sample to 30.0 ∘C and 5.0 atm?

solid → gas The initial point (−60.0 ∘C at 5.0 atm) is located in the solid region and the final point (30.0 ∘C at 5.0 atm) is located in the gas region. However, upon moving from the initial point to the final point, the liquid region is not crossed, so the solid → gas change occurs.