Answer:
333.7g of antifreeze
Explanation:
Freezing point depression in a solvent (In this case, water) occurs by the addition of a solute. The law is:
ΔT = Kf × m × i
Where:
ΔT is change in temperature (0°C - -20°C = 20°C)
Kf is freezing point depression constant (1.86°C / m)
m is molality of solution (moles solute / 0.5 kg solvent -500g water-)
i is Van't Hoff factor (1, assuming antifreeze is ethylene glycol -C₂H₄(OH)₂)
Replacing:
20°C = 1.86°C / m × moles solute / 0.5 kg solvent × 1
5.376 = moles solute
As molar mass of ethylene glycol is 62.07g/mol:
5.376 moles × (62.07g / 1mol) = <em>333.7g of antifreeze</em>.
1 kPa = 7.5 mmHg so 7.0 mmHg / 7.5 mmHg x 1 kPa = .93 kPa
101.3 kPa = 1 atm so 10 kPa / 101.3 kPa x 1 atm = .0987 atm
1 kPa = 7.5 mmHg so 15 kPa x 7.5 mmHg / 1 kPa = 112.5 mmHg
The correct answer is option c, that is, nucleus.
A usual atom comprises three subatomic particles, that is, the neutrons, protons, and electrons. According to Bohr's model, the majority of the mass of an atom is in the nucleus, that is, a small, dense region at the center of each atom, comprising nucleons.
The nucleons incorporate neutrons and protons. All the positive charge of an atom is found in the nucleus and arises from the protons, the neutrons are neutrally-charged, and the electrons are the negatively charged particles found outside of the nucleus.
Answer:
Carbon dioxide is used as a refrigerant, in fire extinguishers, for inflating life rafts and life jackets, blasting coal, foaming rubber and plastics, promoting the growth of plants in greenhouses, immobilizing animals before slaughter, and in carbonated beverages.
Answer: The genotype is the set of genes in our DNA which is responsible for a particular trait. The phenotype is the physical expression, or characteristics, of that trait. For example, two organisms that have even the minutest difference in their genes are said to have different genotypes.
