The answer would be B. An explosion in a chemical reaction that occurs quickly, rust and rotting wood are both chemical but take a long time.
Answer:
39.3%
Explanation:
CaF2 + H2SO4 --> CaSO4 + 2HF
We must first determine the limiting reactant, the limiting reactant is the reactant that yields the least number of moles of products. The question explicitly says that H2SO4 is in excess so CaF2 is the limiting reactant hence:
For CaF2;
Number of moles reacted= mass/molar mass
Molar mass of CaF2= 78.07 g/mol
Number of moles reacted= 11g/78.07 g/mol = 0.14 moles of Calcium flouride
Since 1 mole of calcium fluoride yields two moles of 2 moles hydrogen fluoride
0.14 moles of calcium fluoride will yield 0.14×2= 0.28 moles of hydrogen fluoride
Mass of hydrogen fluoride formed (theoretical yield) = number of moles× molar mass
Molar mass of hydrogen fluoride= 20.01 g/mol
Mass of HF= 0.28 moles × 20.01 g/mol= 5.6 g ( theoretical yield of HF)
Actual yield of HF was given in the question as 2.2g
% yield of HF= actual yield/ theoretical yield ×100
%yield of HF= 2.2/5.6 ×100
% yield of HF= 39.3%
Answer:
12 moles of F₂
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
N₂ + 3F₂ —> 2NF₃
From the balanced equation above,
3 moles of F₂ reacted to produce 2 moles of NF₃.
Finally, we shall determine the number of mole of F₂ needed to produce 8 moles of NF₃. This can be obtained as illustrated below:
From the balanced equation above,
3 moles of F₂ reacted to produce 2 moles of NF₃.
Therefore, Xmol of F₂ will react to produce 8 moles of NF₃ i.e
Xmol of F₂ = (3 × 8)/2
Xmol of F₂ = 12 moles
Thus, 12 moles of F₂ is needed for the reaction.
Answer:
The structures shown by dots and lines to give the exact number of electrons in the outer most shell is explained by Lewis Structures.
Explanation:
Lewis structures are those structures in which the diagram is shown using the electron representation. They are easy to understand as the diagram completely depicts where the electrons are shared and where they are transferred. The diagram also explains where there is a single bond and where there is a di covalent bond or tri covalent bond explaining where the single , double or triple electron pair is shared. The electrons are shown by dots or lines.
For example CCl₄ can be shown as follows
..
.. Cl..
.. ..
..Cl..----------C----------..Cl..
..
.. Cl..
The picture shows that each chlorine has six electrons in its outer shell and then a pair of electron is shared with carbon forming a single covalent bond.
Similarly methane CH4 can also be shown.
The hydrogen has one electron and it shares an electron from carbon stabilising itself forming methane.
Answer:
13.0mL
Explanation:
So this is a classic M1V1=M2V2 problem, where M is molarity and V is volume and the subsequent numbers represent the two sets of condition (1 being before dilution and 2 being after dilution)
So M1 is going to be 5.0M because it is our initial molarity and V1 is what we are trying to find since we are trying to find how much of initial volume should be diluted.
M2 is 1.30M since it is what molarity is after dilution and M2 is what volume is after dilution which is 50mL.
So M1V1=M2V2 (becomes an algebra problem)
5*V1=1.30*50
V1= 13.0mL
Now this answer should make sense since to dilute something with large molarity to small you only need very few mL than the final volume because you add water to dilute it.