Answer:
Explanation:
250 cm^3 of 0.2 moldm-3 H2SO4 can be prepared from 150cm^3 of 1.0 moldm^-3 by dilution.
150cm^3 of the 1.0 moldm^-3 stock solution is measured out using a measuring cylinder and transferred into a 250 cm^3 standard volumetric flask and made up to mark. The resulting solution is now 250cm^3 of 0.2 moldm-3 H2SO4.
The answer is <span>1.63 × 1024 atoms Fe.
</span>
Avogadro's number is the
number of units (atoms, molecules) in 1 mole of substance:
<span>6.023 × 10²³ atoms per 1 mole
</span>So, how many atoms are per 2.70 moles:
6.023 × 10²³ atoms : 1 mole = x : 2.70 moles
x = 6.023 × 10²³ atoms * 2.70 moles : 1 mole
x = 16.3 × 10²³ = 1.63 × 10 × 10²³ = 1.63 × 10²⁴ atoms
Answer:
The steps with correct mechanism are given below:
C
1) CH₄(g) + Cl(g) → CH₃(g) + HCl(g) : This is a slow step.
The rate is given as: R1 = k₁[CH₄][Cl]
2) CH₃(g) + Cl₂(g) → CH₃Cl(g) + Cl(g): This is a fast step.
The rate is given as: Rate = k₂[CH₃][Cl₂]
∴ CH₄(g) + Cl₂(g) → CH₃Cl(g) + HCl(g)
Here, the slowest step will be the rate-determining step.
Answer: 0.5 mole Mg
Explanation: solution:
12 g Mg x 1 mole Mg / 24 g Mg
= 0.5 mole Mg
Answer:
ΔH° = -186.2 kJ
Explanation:
Hello,
This case in which the Hess method is applied to compute the required chemical reaction. Thus, we should arrange the given first two reactions as:
(1) it is changed as:
SnCl2(s) --> Sn(s) + Cl2(g)...... ΔH° = 325.1 kJ
That is why the enthalpy of reaction sign is inverted.
(2) remains the same:
Sn(s) + 2Cl2(g) --> SnCl4(l)......ΔH° = -511.3 kJ
Therefore, by adding them, we obtain the requested chemical reaction:
(3) SnCl2(s) + Cl2(g) --> SnCl4(l)
For which the enthalpy change is:
ΔH° = 325.1 kJ - 511.3 kJ
ΔH° = -186.2 kJ
Best regards.
