There are 115 known elements as of today (Feb. 13, 2016)
so, 'C' is the correct answer
The number of moles of oxygen in the gas is 1.5 L.
The correct option is (A).
<h3>What are moles? </h3>
The mole is the International System of Units' foundation unit of material quantity.
Given,
The volume of gas is 33.6 L
Pressure is 1 atm.
Temperature is 0°C
Molar gas volume is 22.4 L
There is no temperature and pressure is 1 atm.
By formula of moles, volume is divided by molar mass
Thus, option A is correct. 1.5 L.
Learn more about gas, here:
brainly.com/question/13123721
A reaction is first order. If the initial reactant concentration is 0.0200 M, and 25.0 days later the concentration is 6.25 x 10-4 M, then its half-life is:
Answer:
a) Fe(s) + Ni^2+(aq) ----> Fe^2+(aq) + Ni(s)
b) no reaction
c) no reaction
d) 2Mg(s) + 2H2O(l)-----> 2Mg^2+(aq) + O2(g) +4H^+(aq)
e) no reaction
Explanation:
It is important to say here that the ability of a particular chemical specie to displace another chemical specie is dependent on the relative standard reduction potentials of the species involved.
All the reactions stated above are redox reactions. Let us take reaction E as an example. Mg^2+ has a reduction potential of -2.37 V while Cr^3+ has a reduction potential of -0.74V. Since the reduction potential of magnesium is more negative than that of chromium, there is no reaction when a piece of chromium metal is dipped into a solution of Mg^2+.
Similarly, though metals displace hydrogen gas from dilute acids, metals that are less than hydrogen in the reactivity series cannot do that. This explains why there is no reaction when copper and silver are dipped into dilute acid solutions.
Reaction occurs when iron is dipped into a nickel solution because the reduction potential of Fe^2+ is far more negative than that of Ni^2+.
From Boyle's law the volume of a fixed mass of a gas is inversely proportional to the pressure at a constant absolute temperature. Thus; K = PV Hence; P1V1 =P2V2 0.5 × 24 = 4× P2 P2 = 12/4 = 3 atm Therefore; the pressure will go from 24 atm to 3 atm
