Answer:
5.6 seconds
Explanation:
The reaction follows a zero-order in dinitrogen monoxide
Rate = k[N20]^0 = change in concentration/time
[N20]^0 = 1
Time = change in concentration of N2O/k
Initial number of moles of N2O = 300 mmol = 300/1000 = 0.3 mol
Initial concentration = moles/volume = 0.3/4 = 0.075
Number of moles after t seconds = 150 mmol = 150/1000 = 0.15 mol
Concentration after t seconds = 0.15/4 = 0.0375 M
Change in concentration of N2O = 0.075 - 0.0375 = 0.0375 M
k = 0.0067 M/s
Time = 0.0375/0.0067 = 5.6 s
Answer:
Percentage by mass of oxygen = 76.20% (Approx)
Explanation:
Given:
HNO3
H=1, N=14, O=16]
Find:
Percentage by mass of oxygen
Computation:
HNO3
Total mass = 1 + 14 + 3(16)
Total mass = 63
Mass of oxygen = (3)(16) = 48
Percentage by mass of oxygen = [48/63]100
Percentage by mass of oxygen = 76.20% (Approx)
Arsenic, I believe. Metalloids fall in between metals and nonmetals (usually on the bold line separating the two on the periodic table). And since the metalloid in question has four electron shells and five valence electrons in the outermost shell, you can see that this element is arsenic
Answer:
1. 1.25 mol ants x 6.02*10^23 ants/1 mol ants = 7.53*10^23 ants
2. 4.92*10^26 pencils x 1 mol pencils/6.02*10^23 pencils = 817 mol pencils
3. 0.26 mol molecules x 6.02*10^23 molecules/1 mol molecules = 1.6*10^23 molecules
4. 3.46*10^19 molecules x 1 mol molecules/6.02*10^23 molecules = 5.75*10^-5 mol molecules
5. 5.3*10^20 atoms x 1 mol atoms/6.02*10^23 atoms = 8.8 mol atoms
6. 0.11 mol atoms x 6.02*10^23 atoms/1 mol atoms = 6.6*10^22 atoms
I would suggest looking into "dimensional analysis" for help with this type of material. Dimensional analysis will stick with you all throughout chemistry, so picking it up will be extremely beneficial.
Liter. The measure for volume is m^3
