Answer:
Molecular formula
Explanation:
Molecular formula in the first place is required to understand which compound we have. We then should refer to the periodic table and find the molecular weight for each atom. Adding individual molecular weights together would yield the molar mass of a compound.
Then, dividing the total molar mass of a specific atom by the molar mass of a compound and converting into percentage will provide us with the percentage of that specific atom.
E. g., calculate the percent composition of water:
- molecular formula is
; - calculate its molar mass: [tex]M = 2M_H + M_O = 2\cdot 1.00784 g/mol + 16.00 g/mol = 18.016 g/mol;
- find the percentage of hydrogen: [tex]\omega_H = \frac{2\cdot 1.00784 g/mol}{18.016 g/mol}\cdot 100 \% = 11.19 %;
- find the percentage of oxygen: [tex]\omega_O = \frac{16.00 g/mol}{18.016 g/mol}\cdot 100 \% = 88.81 %.
Answer:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
Answer:
Two
Explanation:
Elements in group 16 wants to bond with elements in group IIA, the group of alkaline earth metals.
- The bonding will make it easier for them complete their octet.
- Elements in group 16 has 6 valence electrons.
- To have a complete octet, they require 2 more electrons.
- Group II elements are willing donors as they are metals.
- For Group II elements to fill their octets, they must lose two electrons.
- So the willingness of group II elements to lose two electrons and the readiness for group 16 elements to gain the electrons makes the desire one another.
Answer:
20619.4793 years
Explanation:
The half life of carbon-14 = 5730 years
The formula for the half life for a first order kinetic reaction is:
Where,
is the half life
k is the rate constant.
Thus rate constant is:
5730 years=ln(2)/k
k = 1.21×10⁻⁴ years ⁻¹
Using integrated rate law as:
Where,
is the concentration at time t
is the initial concentration
Given that the final concentration contains 8.25 % of the original quantity which means that:
So,
ln(.0825)= -1.21×10⁻⁴×t
<u>
t = 20619.4793 years</u>
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