The chemical equation is:
CH₄ + 2O₂ → CO₂ + 2H₂O
First, we calculate the moles of methane present using:
Moles = mass / molecular mass
Moles = 20 / 16
Moles = 1.25
Next, we may observe from the chemical equation that the molar ratio between methane and oxygen is 1 : 2
So the moles of oxygen required are 2 x 1.25
2.5 moles of oxygen required
Mass = moles * molecular mass
Mass = 2.5 * 32
Moles = 80
C. 80 grams O₂
Answer:
it is pathogens i think its that
Explanation:
Answer:
333.7g of antifreeze
Explanation:
Freezing point depression in a solvent (In this case, water) occurs by the addition of a solute. The law is:
ΔT = Kf × m × i
Where:
ΔT is change in temperature (0°C - -20°C = 20°C)
Kf is freezing point depression constant (1.86°C / m)
m is molality of solution (moles solute / 0.5 kg solvent -500g water-)
i is Van't Hoff factor (1, assuming antifreeze is ethylene glycol -C₂H₄(OH)₂)
Replacing:
20°C = 1.86°C / m × moles solute / 0.5 kg solvent × 1
5.376 = moles solute
As molar mass of ethylene glycol is 62.07g/mol:
5.376 moles × (62.07g / 1mol) = <em>333.7g of antifreeze</em>.
The terms that apply to this silver necklace are:
pure chemical substance
element
The necklace consists purely of silver, making it a pure chemical substance; moreover, silver itself is an element, not a compound. Therefore, the term element is also fitting for the necklace.
