A pure substance refers to an element or a compound that has no component of another compound or element. Pure substances are made of only one type of atom or molecule. Hydrogen gas and pure iron are examples of pure substances. Hydrogen consists of hydrogen atoms only while iron consists of only iron atoms. Mixing two pure substances results in a mixture. To separate the two, scientists use a method known as filtration. Mixtures can either be homogeneous or heterogeneous. The measure used to determine how pure a substance may be called purity. Besides hydrogen and iron, other pure substances include gold, diamonds, sugar, and baking soda.
Forms when lava and magma cool (A)
Answer:
20.79 kilojoules
Explanation:
Using Q = m×c×∆T
Where;
Q = Quantity of heat (J)
c = specific heat capacity of solid DMSO (1.80 J/g°C)
m = mass of DMSO
∆T = change in temperature
According to the provided information, m= 50g, initial temperature = 19.0°C, final temperature= 250.0°C
Q = m×c×∆T
Q = 50 × 1.80 × (250°C - 19°C)
Q = 90 × 231
Q = 20790 Joules
To convert Joules to kilojoules, we divide by 1000 i.e.
20790/1000
= 20.79 kilojoules
Hence, 20.79 kilojoules of energy is required to convert 50.0 grams of solid DMSO to gas.
Moles of helium is required to blow up a balloon to 87.1 liters at 74 C and 3.5 atm is 021.65 mole
Mole is the unit of amount of substances of specified elementary entities
According to the ideal gas law he number of moles of a gas n can be calculated knowing the partial pressure of a gas p in a container with a volume V at an absolute temperature T from the equation
n =pV/RT
Here given data is volume = 87.1 liters
Temperature = 74 °C means 347.15 k
Pressure = 3.5 atm
R = 0.0821
Putting this value in ideal gas equation then
n =pV/RT
n = 3.5 atm×87.1 liters / 0.0821 ×347.15 k
n = 021.65 mole
Moles of helium is required to blow up a balloon to 87.1 liters at 74 C and 3.5 atm is 021.65 mole
Know more about mole of helium
brainly.com/question/23365554
#SPJ1
Sound waves can move through various mediums. Similar to the way we can hear a car horn from outside of a house, the sound waves will, however dampened, still pass through mediums, in this case being the wall of a house.
