Answer:
Your statement is right.
Explanation:
When fuels are burned in vehicle engines, high temperatures are produced. At this high temperature, nitrogen and oxygen from the air combine with each other to produce nitrogen monoxide (NO). When this nitrogen monoxide is released in the air from vehicle exhaust systems, it combines with oxygen present in the air to form nitrogen dioxide (NO2).
Distinguish the difference between physical change or chemical change.
Should be C.
Manipulated variable: the types of soil
Responding variable: how much t the plants grow
Answer:lower temp molecules act slower so they come closer together and heated molecules are more spaced out that is why when you put an ice cube in a hot pan the ice melts and turns into a liquid due to heat the molecules space out
Explanation:
Answer:
(a) oxygen
(b) 154g (to 3sf)
(c) 79.9% (to 3sf)
Explanation:
mass (g) = moles × Mr/Ar
note: eqn means chemical equation
(a)
moles of P = 84.1 ÷ 30.973 = 2.7152 moles
moles of O2 = 85÷2(16) = 2.65625 moles
Assuming all the moles of P is used up,
moles of O2 / moles of phosphorus = 5/4 (according to balanced chemical eqn)
moles of O2 required = 5/4 × 2.7152moles = 3.394 moles (more than supplied which is 2.65625moles)
therefore there is insufficient moles of O2 and the limiting reactant is oxygen.
(b)
moles of P2O5 produced
= 2/5 (according to eqn) × 2.7152
= 1.08608moles
mass of P2O5 produced
= 1.08608 × [ 2(30.973) + 5(16) ]
= 154.164g
= approx. 154g to 3 sig. fig.
(c)
% yield = actual/theoretical yield × 100%
= 123/154 × 100%
= 79.870%
= approx. 79.9% (to 3sf)
