Answer:
The answer to your question is: 58.4 g of NaCl
Explanation:
Data
Volume = 200 ml = 0.2 l
Concentration = 5M
MW = 58.4 g
mass NaCl = ?
Formula
Molarity = (# of moles ) / volume
# of moles = Molarity x volume
# of moles = 5 x 0.2
# of moles = 1
58.4 g ---------------------- 1 mol
x --------------------- 1 mol
x = (1 x 58.4) / 1
x = 58.4 g of NaCl
Answer: Heat dissipation mechanism
Explanation: Heat dissipation mechanism is a thermoregulatory response in humans whereby the hypothalamus of the brain initiates certain processes to reduce the high body temperature. Eg, sweating is initiated which helps cool down the body temperature, also superficial arteries are dilated, thereby leading to flushing and decreasing heatloss into the air. And metabolic heat production is also reduced.
Answer:
An alkali metal present in period 2 have larger first ionization energy.
Explanation:
Ionization energy:
The amount of energy required to remove the electron from the atom is called ionization energy.
Trend along period:
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.
Trend along group:
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. Thus alkali metal present in period 2 have larger ionization energy because of more nuclear attraction as compared to the alkali metal present in period 4.
Answer:
Option D. Al is above H on the activity series.
Explanation:
The equation for the reaction is given below:
2Al + 6HBr —> 2AlBr₃ + 3H₂
The activity series gives us a background understanding of the reactivity of elements i.e how elements displace other elements when present in solution.
From the activity series of metals, we understood that metal higher in the series will displace those lower in the series.
Considering the equation given above, Al is higher than H in the activity series. Thus, the reaction will proceed as illustrated by the equation.
Therefore, we can conclude that the reaction will only occur if Al is higher than H in the activity series.
