The correct answer is:
C. valence.
Explanation:
The valence or valency of an element is a stratagem of its connecting power with other atoms when it makes chemical compounds or molecules.
A valence electron is an outer shell electron that is connected with an atom, and that can compete in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond provide one valence electron in order to form a shared pair
The balanced equation would be:
2HCl + Mg(HCO3)2 —> MgCl2 + 2CO2 + 2H2O
Answer:
T₂ = 319.13 K
Explanation:
Given data:
Initial volume of gas = 1.16 L
Initial temperature = 23°C
Final temperature = ?
Final volume = 1.25 L
Solution:
Initial temperature = 23°C (23+273.15 = 296.15 K)
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
T₂ = V₂ T₁ / V₁
T₂ = 1.25 L × 296.15 K / 1.16 L
T₂ = 370.19 L.K / 1.16 L
T₂ = 319.13 K
First, let's determine the number of moles of carbon atoms by using molar mass. Then, using Avogadro's number, we can find the number of C atoms:
*1 mole of C3H8O= (12.0x3)+(1.0x8)+(16.0x1) = 60.0g/mol
25.0 grams C3H8O x (1 mole C3H8O/60.0 grams) = 0.417 mol
0.417mol C3H8O has (3 x 0.417 moles) C atoms = 1.251 moles C atoms
1.251 moles C atoms x(6.022x10^23 atoms/mol) = 9.42x10^23 C atoms.
The answer is in 3 significant figures, as that's what we have in the given, and we matched it with our rounding of the atomic masses from the periodic table.
You can do this all in one equation written left to right, just exclude the intermediate answers. Just easier to show it this way on the computer screen.
