Answer is: adding NaCl will lower the freezing point of a solution.
A solution (in this example solution of sodium chloride) freezes at a lower temperature than does the pure solvent (deionized water).
The higher the solute concentration (sodium chloride), freezing point depression of the solution will be greater.
Equation describing the change in freezing point:
ΔT = Kf · b · i.
ΔT - temperature change from pure solvent to solution.
Kf - the molal freezing point depression constant.
b - molality (moles of solute per kilogram of solvent).
i - Van’t Hoff Factor.
Dissociation of sodium chloride in water: NaCl(aq) → Na⁺(aq) + Cl⁻(aq).
Answer:
The structures shown by dots and lines to give the exact number of electrons in the outer most shell is explained by Lewis Structures.
Explanation:
Lewis structures are those structures in which the diagram is shown using the electron representation. They are easy to understand as the diagram completely depicts where the electrons are shared and where they are transferred. The diagram also explains where there is a single bond and where there is a di covalent bond or tri covalent bond explaining where the single , double or triple electron pair is shared. The electrons are shown by dots or lines.
For example CCl₄ can be shown as follows
..
.. Cl..
.. ..
..Cl..----------C----------..Cl..
..
.. Cl..
The picture shows that each chlorine has six electrons in its outer shell and then a pair of electron is shared with carbon forming a single covalent bond.
Similarly methane CH4 can also be shown.
The hydrogen has one electron and it shares an electron from carbon stabilising itself forming methane.
6 Atoms!
Mg = 1 atom.
O = 4 atoms.
A = 1 atom.
(1)
The health of coral colonies
The levels of carbon dioxide in the atmosphere
This is because corals are very sensitive to changes in the ocean's properties pH being included. Warmer oceans dissolves more carbon dioxide from the atmosphere hence making the waters slightly acidic. This will affect coral resulting in bleaching. This negatively affects the marine ecosystems since corals are usually at the bottom of the energy pyramid in these ecosystems.
(2)
Chlorofluorocarbons are very harmful to the environment when released into the atmosphere. They damage the ozone layer and therefore allow more UV rays from sunlight to reach the earth’s surface. They also have a greenhouse effect causing the earth’s atmosphere to warm up. This ultimately leads to global warming and climate change.
(3)
It would allow storm systems to stall in an area
Jets streams are very significant in that they influence weather patterns across the world. They are responsible for the movement of pressure systems and global air cells and their accompanying weather patterns. Because they generally sit in between cold and warm air systems they are significant in moving these air masses around. When they are weak they cause an air system to linger including storms causing excessive flooding in an area.
(4)
Absorb and re-emit infrared radiation.
Produced by human activity
Greenhouse gases do not allow infrared radiation from the earth's surface to escape back to space. Infrared is the electromagnetic wave spectrum responsible for transferring heat energy. Therefore, when left to linger in the atmosphere, they cause the greenhouse effect. This is the reason for global warming.
(5)
Air temperature –, ice
Ocean temperature – ice, a chemical isotope of <em>foraminifera</em>
Carbon dioxide levels – a chemical isotope of <em>foraminifera</em>
Kind of plants – fossilized pollen grains
Rainfall- the rings
<h3>
Answer:</h3>
42960 years
<h3>
Explanation:</h3>
<u>We are given;</u>
- Remaining mass of C-14 in a bone is 0.3125 g
- Original mass of C-14 on the bone is 80.0 g
- Half life of C-14 is 5370 years
We are required to determine the age of the bone;
- Remaining mass = Original mass × 0.5^n , where n is the number of half lives.
Therefore;
0.3125 g = 80.0 g × 0.5^n
3.90625 × 10^-3 = 0.5^n
- Introducing logarithm on both sides;
log 3.90625 × 10^-3 = n log 0.5
Solving for n
n = log 3.90625 × 10^-3 ÷ log 0.5
= 8
- Therefore, the number of half lives is 8
- But, 1 half life is 5370 years
- Therefore;
Age of the rock = 5370 years × 8
= 42960 years
Thus, the bone is 42960 years old
