Answer:
stochiometry works with measuring quantitative relationships and used to determine the amount of products and reactants that are produced or needed in a reaction
Answer: Be= 2, C =4, Li = 1 and B=3
Explanation:
The valence shell can be define as the outermost shell of an atom that contains the valence electrons.
Beryllium (Be), electronic configuration; 1s2 2s2, = 2 electrons in its valence shell.
Carbon (C), electronic configuration; 1s2 2s2 2p2, = 4 electrons in its valence shell.
Lithium (Li), electronic configuration; 1s2 2s1 = 1 electron in its valence shell.
Boron (B) , electronic configuration; 1s2 2s2 2p1 = 3 electron in its valence shell.
<u>Answer:</u> The half life of the sample of silver-112 is 3.303 hours.
<u>Explanation:</u>
All radioactive decay processes undergoes first order reaction.
To calculate the rate constant for first order reaction, we use the integrated rate law equation for first order, which is:
![k=\frac{2.303}{t}\log \frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%20%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = ?
t = time taken = 1.52 hrs
= Initial concentration of reactant = 100 g
[A] = Concentration of reactant left after time 't' = [100 - 27.3] = 72.7 g
Putting values in above equation, we get:

To calculate the half life period of first order reaction, we use the equation:

where,
= half life period of first order reaction = ?
k = rate constant = 
Putting values in above equation, we get:

Hence, the half life of the sample of silver-112 is 3.303 hours.
Answer:
70mol
Explanation:
The equation of the reaction is given as:
2C₂H₂ + 5O₂ → 4CO₂ + 2H₂O
Given parameters:
Number of moles of acetylene = 35.0mol
Number of moles of oxygen in the tank = 84.0mol
Unknown:
Number of moles of CO₂ produced = 35.0mol
Solution:
From the information given about the reaction, we know that the reactant that limits this combustion process is acetylene. Oxygen is given in excess and we don't know the number of moles of this gas that was used up. We know for sure that all the moles of acetylene provided was used to furnish the burning procedure.
To determine the number of moles of CO₂ produced, we use the stoichiometric relationship between the known acetylene and the CO₂ produced from the balanced chemical equation:
From the equation:
2 moles of acetylene produced 4 moles of CO₂
∴ 35.0 mol of acetylene would produced:
= 70mol
Answer:
The correct answer is option B
Explanation:

Given values,
Molarity of 
Volume of solution, 
Molecular weight of 
Substituting this values in Molarity formula, we get
