Answer:
6.24%
Explanation:
Molality by definition means a measurement of the number of moles of solute in solution with 1000 gm or 1Kg solvent. Notice the difference that Molarity is defined on the volume of solution and Molality on the mass of solvent.
So, An aqueous solution of iron(II) iodide has a concentration of 0.215 molal.
means 0.215 moles are present in 1 Kg of solvent.
The molar mass of Fe2I = 309.65 g / mole
mass of FeI2 = moles x molar mass
= 0.215 x 309.65
=66.57 gm
mass % of FeI2 = mass of FeI2 x 100 / total mass
= 66.57x 100 / (1000 +66.57)
= 6.24%
Answer:
1. Covalent bonds can form between two nonmetal atoms.
2. Covalent bonds can form between atoms of the same element.
3. Covalent bonds can form between atoms of different elements.
Explanation:
I hope this helps u! :D
Explanation:
The answer to the question given above is letter A. Light
Light is considered a load of the parts of a circuit. <span>The load in a circuit can be
any electrical device that converts electrical energy into other usable forms
of energy such as a <span>light bulb.
>></span></span><span>Energy sources include
batteries and generating stations
>>switch-</span><span>is
used in electric circuits to allow the circuit to be turned on and off.</span>
Answer:
cream - contains a higher proportion of oil than water
ointment - dr4g mixed in approximately equal proportions of oil and water
i don't know about the other two sorry
Answer:
3,964 years.
Explanation:
- It is known that the decay of a radioactive isotope isotope obeys first order kinetics.
- Half-life time is the time needed for the reactants to be in its half concentration.
- If reactant has initial concentration [A₀], after half-life time its concentration will be ([A₀]/2).
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
- The half-life of the element is 5,730 years.
- For, first order reactions:
<em>k = ln(2)/(t1/2) = 0.693/(t1/2).</em>
Where, k is the rate constant of the reaction.
t1/2 is the half-life of the reaction.
∴ k =0.693/(t1/2) = 0.693/(5,730 years) = 1.21 x 10⁻⁴ year⁻¹.
- Also, we have the integral law of first order reaction:
<em>kt = ln([A₀]/[A]),</em>
where, k is the rate constant of the reaction (k = 1.21 x 10⁻⁴ year⁻¹).
t is the time of the reaction (t = ??? year).
[A₀] is the initial concentration of the sample ([A₀] = 100%).
[A] is the remaining concentration of the sample ([A] = 61.9%).
∴ t = (1/k) ln([A₀]/[A]) = (1/1.21 x 10⁻⁴ year⁻¹) ln(100%/61.9%) = 3,964 years.
