Correct answer: B
Cooling curve is the plot of temperature versus time as the sample is allowed to cool. In a cooling curve, we start at a temperature greater than the boiling point. At this temperature, the sample is in gaseous state. At the boiling point, there is no change in temperature as the gaseous and liquid states are in equilibrium. As the temperature reduces further, the liquid starts to condense and at the melting point of the sample the liquid undergoes phase transition to solid state. At the melting temperature, a second plateau is observed as the temperature remains unchanged. At temperatures below the melting point, the sample exists as a solid.
So from the curve, the second plateau is observed at around -111
. This point represents the phase transition from liquid to solid state.
The answer is B. The complete equation is C6H12O6 + 6O2 -->6H2O + 6CO2 + energy. So we can know that A and C and D is right. For B, the reaction release energy so it is exothermic reaction.
<h3><u>Answer;</u></h3>
They are made up of elements.
<h3><u>Explanation;</u></h3>
- An atom is the smallest particle of matter that still retains the property of the element.
- Two or more atoms combine to form elements or compounds. Elements are formed by two or more similar atoms, while compounds are formed by two or more different elements.
- Atoms are made up of subatomic particles; protons, electrons and neutrons. Electrons are negatively charged, protons are positively charged while neutrons have no charge.
The amount of sugar is 2621 mg
Why?
The complete question is:
A 12.630 g milk chocolate bar is found to contain 8.315 g of sugar.
Part B. What will be the amount of sugar in milligrams if the size of the milk chocolate bar is reduced from 12.630 g to 4.000 g ?
To find the answer we have to determine first the amount of sugar in milligrams per gram of chocolate bar. We can find that by applying the following conversion factor:
Now, we have to determine the amount of sugar in milligrams if we had a chocolate bar with 4.000 g:
Have a nice day!
Colligative properties are those substances that depend
on the number of substances in the solution, not in the identity of that
substance. The property changes the way that it does when the amount of solute
is increased because it enables the solute to be scattered more. For example,
the freezing point of salt water is lower than that of the pure water due to
the salt ions present in water.
