15.5% by mass is
equivalent 15.5 g urea in 100 g solution or 155 g urea in 1 kg solution. <span>
<span>we know that molality = moles solute / kg solvent
<span>moles solute = 155 g / 60 g/mol = 2.58 moles urea
</span></span></span>
Since there are 155 g
urea in 1000g solution, hence the solvent is 845 g or 0.845 kg
So:<span>
<span>molality = 2.58 / 0.845 = 3.06 m</span></span>
Answer:
The pressure of N₂ gas in cylinder B when compressed at constant temperature increases due to the increase in the frequency of collision between the gas molecules with themselves and with the wall of their container caused by a decrease in volume of the container.
Explanation:
Gas helps to explain the behavior of gases when one or more of either temperature, volume or pressure is varying while the other variables are kept constant.
In the gas cylinder B, the temperature of the given mass of gas is kept constant, however, the volume is decreased by pushing the movable piston farther into the cylinder. According to the gas law by Robert Boyle, the volume of a given mass of gas is inversely proportional to its pressure at constant temperature. This increase in pressure is due to the increase in the frequency of collision between the gas molecules with themselves and with the wall of their container caused by a decrease in volume of the container. As the cylinder becomes smaller, the gas molecules which were spread out further become more packed closely together, therefore, their frequency of collision increases building up pressure in the process.
Answer:
The initial temperature of the metal is 84.149 °C.
Explanation:
The heat lost by the metal will be equivalent to the heat gain by the water.
- (msΔT)metal = (msΔT)water
-32.5 grams × 0.365 J/g°C × ΔT = 105.3 grams × 4.18 J/g °C × (17.3 -15.4)°C
-ΔT = 836.29/12.51 °C
-ΔT = 66.89 °C
-(T final - T initial) = 66.89 °C
T initial = 66.89 °C + T final
T initial = 66.89 °C + 17.3 °C
T initial = 84.149 °C.
Answer: The author used the word "conversely" because the first statement he made is in CONTRAST to the second statement he made.
Explanation:
Matter is made up of atoms or molecules that are in constant motion. The motion of these tiny particles ( molecules) gives the object energy. The movement of these molecules depends on the state of matter which includes
--> GASEOUS STATE: Here, the particles are completely free to move and are always in motion.
--> LIQUID STATE: particles in this state slide by one another and are always in motion.
--> SOLID STATE: particles in this state are held tightly together but are always in motion.
Also, the molecules in motion are greatly affected by temperature changes. Increase in temperature will cause the particles in the liquid to move faster. Such is seen when soup is heated, the molecules travel faster than before. But the OPPOSITE is seen in an ice cube. This is because the ice cube is in solid state and of a lower temperature.
