Answer:
Exothermic reaction for the HCl, endothermic reaction for the water
Explanation:
Heat was lost by HCl as its temperature lowered, so it was an exothermic reaction for the HCL.
Heat was gained by water as its temperature increased, so it was an endothermic reaction for the water.
m = Mass of water = 100 g
c = Specific heat of water = 
= Change in temperature of water = 
Heat is given by
Heat gained by water is .
Answer:
<em>When salt is dissolved in water</em>, many physical properties change, among them the so called colligative properties:
- The vapor pressure of water decreases,
- The boiling point increases,
- The freezing point decreases, and
- Osmotic pressure appears.
Explanation:
Colligative properties are the physical properties of the solvents whose change is determined by the number of particles (moles or ions) of the solute added.
The colligative properties are: vapor pressure, boiling point, freezing point, and osmotic pressure.
<u>Vapor pressure</u>:
The vapor pressure is the pressure exerted by the vapor of a lquid over its surface, in a closed vessel.
The vapor pressure increases when a solute is added, because the presence of the solute causes less solvent molecules to be near the surface ready to escape to the vapor phase, which means that the vapor pressure is lower.
<u>Boiling point</u>:
The boiling point is the temperature at which the vapor pressure of the liquid equals the atmospheric pressure. Since we have seen that the vapor pressure of water decreases when a solute occupies part of the surface, now more temperature will be required for the water molecules reach the atmospheric pressure. So, the boiling point increases when salt is dissolved in water.
<u>Freezing point</u>:
The freezing point is the temperarute at which the vapor pressure of the liquid and the solid are equal. Since, the vapor pressure of water with salt is lower than that of the pure water, the vapor pressure of the liquid and solid with salt will be equal at a lower temperature. Hence, the freezing point is lower (decreases).
<u>Osmotic pressure</u>:
Osmotic pressure is the additional pressure that must be exerted over a solution to make that the vapor pressure of the solvent in the solution equals the vapor pressure of the pure solvent. This additional pressure is proportional to the concentration of the solute: the higher the salt concentration the higher the osmotic pressure.
Answer:
2.0 moles
Explanation:
I hope this helps you a little bit at least the answer is 2.0 but if you want to review more stuff check the photos
4. True
5. The amplitude of the ripples decreases as the circumference of the circle increases.
<h3>What is a wave?</h3>
A wave is a disturbance that moves energy from one place to another.
Radio waves, gamma-rays, visible light, and all the other parts of the electromagnetic spectrum are electromagnetic radiation. Electromagnetic radiation can be described in terms of a stream of mass-less particles, called photons, each travelling in a wave-like pattern at the speed of light. Hence, the statement is true.
As the disturbance moves outwards the energy it carries is spread over a larger and larger region called the wavefront. For example, the ripples in the water lie in a circle with an ever-increasing circumference. The amplitude of the ripples decreases as the circumference of the circle increases.
Learn more about the Electromagnetic wave here:
brainly.com/question/3101711
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Answer:
the answer is nitrogen and rubidium (C)
Explanation:
ionic bonds only form between metals and non-metals
