A material will change from one state or phase to another at specific combinations of temperature and surrounding pressure. Typically, the pressure is atmospheric pressure, so temperature is the determining factor to the change in state in those cases.
Names such as boiling and freezing are given to the various changes in states of matter. The temperature of a material will increase until it reaches the point where the change takes place. It will stay at that temperature until that change is completed.
Answer:
Explanation:
Driving a car (burning gas is a chemical change) and almost all the plastics we use are made by chemical reactions of different components.
Enzymes are needed for metabolic pathways in the body, respiration, digestion and other important life processes. When enzymes function properly, homeostasis is maintained. However, if an enzyme is lacking or has an incorrect shape due to genetic mutation, this can lead to disease within an organism.
Answer:
a) 7.0.
b) Nickel sulfate hepta hydrate.
c) 280.83 g/mol.
d) 44.9%.
Explanation:
<u><em>a) What is the formula of the hydrate?</em></u>
The mass of the hydrated sample (NiSO₄.xH₂O) = 5.0 g,
The mass of the anhydrous salt (NiSO₄) = 2.755 g,
The mass of water = 5.0 g - 2.755 g = 2.245 g.
∴ no. of moles of water = mass/molar mass = (2.245 g)/(18.0 g/mol) = 0.1247 mol.
∴ no. of moles of anhydrous salt (NiSO₄) = mass/molar mass = (2.755 g)/(154.75 g/mol) = 0.0178 mol.
∴ water of crystallization in the sample (x) = no. of moles of water/no. of moles of anhydrous salt (NiSO₄) = (0.1247 mol)/(0.0178 mol) = 7.0.
<u><em>b) What is the full chemical name for the hydrate?</em></u>
The name of the salt (NiSO₄.7H₂O) is Nickel sulfate hepta hydrate.
<u><em>c) What is the molar mass of the hydrate? </em></u>
(NiSO₄.7H₂O)
The molar mass = molar mass of NiSO₄ + 7(molar mass of H₂O) = (154.75 g/mol) + 7(18.0 g/mol) = 280.83 g/mol.
<em><u>d) What is the mass % of water in the hydrate?</u></em>
The mass % of water = (mass of water)/(mass of hydrated sample) x 100 = (2.245 g)/(5.0 g) x 100 = 44.9%.
