Answer:
Explanation:
21. Atoms are not created or destroyed means that atoms that you begin with are the atoms that you will end with. The catch is that the atoms will rearrange to give you new compounds, but the atoms that you initially had are the atoms you will still have after reaction. For eg, if you started with eggs and made omelet. Omelet is a "new" compound, but the atoms that were in the eggs have rearranged to become the omelet so can you see that atoms were not created or destroyed to make the omelet.
22. Yes because amount of products you make depends on how much reactants you have. For eg, I need two graham cracker(GC), one marshmallow(M), and one chocolate (C) to make a s'more. If I get more of each item then I can make more s'mores and consequently having minimum amounts results in less s'mores that I make.
23. Not possible, due to law of conservation of matter and energy. Atoms cannot be created nor be destroyed, they are simply rearranged. For eg, Taking A + B cannot give you a new compound with a chemical formula D or XZ. A + B can however give you AB which is rearrangement of the starting atoms.
24. Chemical equation is balanced when atoms on reactant side and atoms of product side are in equal counts. I have attached a graphic below for more help.
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.
Pressure in the submarine when the temperature is changed to 293 K is 108.9 K Pa
Explanation:
Pressure in the submarine = 108.9 kPa
Volume, V = 2.4 * 10^5 L
Pressure, P = 116k Pa
Temperature, T = 312 K
Ideal gas law: PV = nRT or n = PV / RT
So, moles of gas, n =116 KPa * 2.4 * 10 ^5L / 8.314 LK Pa K^-1 *312 K
= 1.073 *10^4 mol
when temperature is changed to 293K,
PV = nRT or P = nRT / V
=1.073 *10^4 mol *8.314 LK Pa mol^-1 K^-1 *293 K / 2.4*10^5L
=108.9 K Pa
Pressure in the submarine when the temperature is changed to 293 K is 108.9 K Pa
Answer:
a) is correct.......,.....
