Missing question:<span> How many grams of oxygen are needed for complete combustion of the toluene?
Chemical reaction: </span>C₇H₈ + 9O₂ → 7CO₂ + 4H₂<span>O.
V(</span>C₇H₈) = 8,30 ml.
d(C₇H₈) = 0,867 g/ml.
n(C₇H₈) = V(C₇H₈) · d(C₇H₈).
m(C₇H₈) = 8,3 ml · 0,867 g/ml.
m(C₇H₈) = 7,19 g.
n(C₇H₈) = m(C₇H₈) ÷ M(C₇H₈).
n(C₇H₈) = 7,19 g ÷ 92,14 g/mol = 0,078 mol.
From chemical reaction: n(C₇H₈) : n(O₂) = 1 : 9.
n(O₂) = 9 · 0,078 mol = 0,702 mol.
m(O₂) = 0,702 mol · 32 g/mol = 22,5 g.
Answer: Here comes the role of another formula, which we refer to as the structural formula and that is CH3OH for methanol. The structural formula gives us an additional information that carbon is attached to three hydrogen atoms and one oxygen atom.
The answer is C. No all cells have cell walls. Prokaryotes don’t have a nucleus or chloroplast. Leaving C to be correct
Electric current is when electrons start to flow around a circuit. We use an ammeter to measure it and it is measured in amps
Potential difference (also called voltage) is how big the push on the electrons is. We use a voltmeter to measure it and it is measured in volts.
Resistance is anything that resists an electric current. It is measured in ohms”.
(Words: volts, amps, ohms, voltage, ammeter, voltmeter).
