Answer:
Quantity of Carbon is 4.09 gm
Explanation:
Equation of carbon reacting with oxygen to give carbon dioxide is given by
C + 
⇒ C
One mole of carbon reacts with one mole of Oxygen in this reaction to give One mole of Carbon dioxide.
So, 12 gm of carbon reacts with 32 gm of Oxygen in this reaction to give 44 gm of carbon dioxide.
15 gm of C was formed in this reaction
Oxygen used in this reaction = 
×32 = 10.91 gm ,
Thus Oxygen is in sufficient quantity in the reaction.
Now,
Carbon that must be used = ×12 = 4.09 gm.
Answer:
8 neutrons
A is the number of neutrons plus protons in the nucleus. However, we already know that there are 7 protons. Therefore, there must be 8 neutrons in the nucleus to add up to 15. Table 3.
Element Symbol Number of Neutrons
carbon 146C 8
nitrogen 147N 7
157N 8
oxygen 168O 8
Explanation:
A:- sn(s) => Sn +2(0.24 M) + 2e-
B:- Sn +2 (0.87 M) +2e- => Sn(s)
solution will become more concentrated and solution B become less concentrated
Sn(s)+ Sn +2(0.87 ) ----> Sn(s) + Sn +2(0.24)
E = Eo - 0.0592 / 2 * log [ (0.24 / 0.87 ) ]
E = 0.0 - 0.0592 / 2 * log ( 0.275)
( n=2 two electrons are transferred)
E = -0.0296 * ( - 0.560)
E = 0.0165 volts
Molality= moles NaCl/ Kg H2O
250 g (1 Kg/ 1000 grams)= 0.250 Kg
Molality= 0.611 moles/ 0.250 Kg= 2.44 molal
Answer:
a) Na
c) Na
b) Sr
d) Ca
Explanation:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
