Answer:
Energy is added (postive enthalpy)
Explanation:
Ice melting means solid turns into liquid. Solid is more stable than liquid thus you must put in energy to weaken the forces of solid and turn it into liquid. Thus, you must put in energy to melt ice. This makes the enthalpy of the system to be positive.
Scientists can measure the height in
different units but problem could arise when they compare all the measurements.
That is the reason there is standard units for measurements.
<span>There may be error arises when an
American scientist is measuring the height of an object in inches and other Australian
scientist is measuring the height of same object in meters. Their data cannot
be compared because they are using different units to measure height.</span>
Salt dissolved in water is a solution, therefore
- salt is not chemically bonded to water
- the ratio of salt to water may vary
- salt and water retain their own chemical properties
<u>Explanation:</u>
Salt (sodium chloride) is formed from positive sodium ions bonded to negative chloride ions. Water can dissolve salt because the positive part of water particles attracts the negative chloride ions of salt. The water particle effects to be charged negatively near the atom of oxygen and positively near the atom of hydrogen.
Since contrasts attract, the water molecules tend to join collectively like magnets. Water is called the universal solvent since it can solve more substances than any other liquid. The salt and water retain their unique chemical properties.
Answer:
The reaction rate or rate of reaction is the speed at which a chemical reaction takes place, defined as proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time. Reaction rates can vary dramatically.
This can be solve using the grahams law, which states that the rate of diffusion of the gas is inversely proportional the square root of the molar mass of the gas. meaning the gas with smaller molar mass is the fastest to diffuse
molar mass of the following
F2 = 38 g/mol
CO2 = 44 g/mol
He = 4 g/mol
SO2 = 64 g/mol
NO = 30 g/mol
NH3 = 17 g/mol
so the fastest is He
