Answer:
We need 12.26 grams H2SO4
Explanation:
Step 1: Data given
Volume of a H2SO4 solution = 500 mL = 0.500 L
Concentration of the H2SO4 solution = 0.250 M
Molar mass of H2SO4 = 98.08 g/mol
Step 2: Calculate moles H2SO4
Moles H2SO4 = concentration * volume
Moles H2SO4 = 0.250 M * 0.500 L
Moles H2SO4 = 0.125 moles
Step 3: Calculate mass of H2SO4
Mass of H2SO4 = moles * molar mass
Mass of H2SO4 = 0.125 moles * 98.08 g/mol
Mass of H2SO4 = 12.26 grams
We need 12.26 grams H2SO4
One half-life: 5 grams
Two half-lives: 2.5 grams
The mass of pentane the student should weigh out is
The density of pentane is 0.626 gcm-3
To calculate the mass of pentane following expression is used,
(Density is defined as the mass divide by volume)
Density = mass / volume
mass of pentane = Density of pentane * Volume of pentane
mass of pentane = 0.626 gcm-3 * 45.0 mL
= 28.17 g
Here the unit of mass of pentane is g,
However the unit of density is gcm-3 and unit of volume is mL i.e. cm3
Hence, Mass = gcm-3 * cm3
Mass = g
The mass of pentane the student should weigh out is 28.17g
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Explanation:
the volume and temperature of a gas have a ditect relationship,as the temperature increases the volume also increases when pressure is held constand, heating the gas increases the kinetic energy of the particles or atoms,causing the gas to expand until the pressure returns to its original value