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)
Answer:
Explanation:
A1. Chemical indicator, any substance that gives a visible sign, usually by a colour change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow colour to an alkaline solution.
A2. The reaction of an acid with a base is called a neutralization reaction. The products of this reaction are a salt and water. ... For example, the reaction of hydrochloric acid, HCl, with sodium hydroxide, NaOH, solutions produces a solution of sodium chloride, NaCl, and some additional water molecules
A3. Methyl orange has the property to color alkaline and neutral water yellow. If the water becomes acidic, it turns red immediately.
Answer:
acquired/harmful
Explanation:
This type of mutation and exposure will cause indefinite problems.
Answer: The correct option is Current W flows at a higher rate than Current Z.
Explanation: To answer this question, we will require Ohm's law.
Ohm's Law states that the current flowing through a conductor across two points is directly proportional to the voltage difference across that two points.
Mathematically,
where, V = voltage
I = Current
R = resistance
For the given question, assuming that the resistance is constant. So, the current is directly proportional to the voltage.
Hence, as the current W is greater of all the given currents so, it will flow at a higher rate.
Therefore, the correct answer is Current W flows at a higher rate than Current Z.
