The boiling point of water at 1 atm is 100 degrees celsius. However, when water is added with another substance the boiling point of it rises than when it is still a pure solvent. This called boiling point elevation, a colligative property. The equation for the boiling point elevation is expressed as the product of the ebullioscopic constant (0.52 degrees celsius / m) for water), the vant hoff factor and the concentration of solute (in terms of molality).
ΔT(CaCl2) = i x K x m = 3 x 0.52 x 0.25 = 0.39 °C
<span> ΔT(Sucrose) = 1 x 0.52 x 0.75 = 0.39 </span>°C<span>
</span><span> ΔT(Ethylene glycol) = 1 x 0.52 x 1 = 0.52 </span>°C<span>
</span><span> ΔT(CaCl2) = 3 x 0.52 x 0.50 = 0.78 </span>°C<span>
</span><span> ΔT(NaCl) = 2 x 0.52 x 0.25 = 0.26 </span>°C<span>
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Thus, from the calculated values, we see that 0.75 mol sucrose dissolved on 1 kg water has the same boiling point with 0.25 mol CaCl2 dissolved in 1 kg water.
The question is incomplete, the complete question is;
Which statement describes a difference between electromagnetic and mechanical waves?
A. Mechanical waves cannot be longitudinal, but electromagnetic waves can.
B. Electromagnetic waves cannot move particles, but mechanical waves can.
C. Electromagnetic waves do not require a medium, but mechanical waves do.
D. Mechanical waves do not transfer energy, but electromagnetic waves do.
Answer:
Electromagnetic waves do not require a medium, but mechanical waves do.
Explanation:
A wave is defined as a disturbance along a medium which transfers energy. Waves may be classified as mechanical waves or electromagnetic waves based on their medium of propagation.
A mechanical wave requires a material medium for propagation. An example of a mechanical wave is sound waves. Sound waves are propagated in air.
Electromagnetic waves do not require a material medium for propagation. They can travel through space. An example of electromagnetic waves is light waves.
Explanation:
mass number= atomic number + no of neutrons
35= 17 + no of neutrons
no of neutrons = 18
Answer:
Antibiotic resistance happens when the germs no longer respond to the antibiotics designed to kill them. That means the germs are not killed and continue to grow. It does not mean our body is resistant to antibiotics.
