Answer:
Oversight of weights and measures ensures correct evaluations of goods and services so that everyone receives a fair exchange in the marketplace. It also acts as a deterrent, promoting honesty among traders.
Explanation:
Answer:
- A. Which element, X or Z, has a higher molar mass?
Explanation:
Heating the original compounds intensely to remove all oxygen causes chemical decomposition reactions:
- 2XClO₃ (solid) → 2XCl + 3O₂ (gas)
- 2ZClO₃ (solid) → 2ZCl + 3O₂ (gas)
By measuring the initial mass of each sample and the mass remaining after heating, the student can compute the oxygen gas mass released:
- Mass of oxygen released = initial sample mass minus residue mass
Using this oxygen mass, she can calculate how many moles of oxygen were present in each sample:
- Moles of oxygen = oxygen mass (g) divided by molar mass of oxygen
Next, the moles of the original sample are determined:
- Each mole of XClO₃ or ZClO₃ has 3 moles of oxygen atoms.
So, dividing the moles of oxygen released by 3 gives the moles of the sample.
Applying the formula molar mass = mass / moles, the student finds the molar masses of XClO₃ and ZClO₃.
Thus, this data allows answering question A: Which of X or Z has the higher molar mass?
The slight warm feeling noticed at the valve stem when air is pumped into the tire is likely due to the kinetic energy generated by the friction from the pump and the resultant increase in gas pressure within the tire.
Response:
To reach the answer, 465.6 mg of MgI₂ is required.
Detailed Explanation:
We need to establish the moles of ion I⁻ in the resulting solution.
C = n/V -> n = C x V = 0.2577 (L) x 0.1 (mol/L) = 0.02577 mol.
In the initial solution, there was 0.087 M KI, which we can similarly convert into moles, yielding 0.02242 mol.
This indicates we require an additional amount of 0.02577 - 0.02242 = 0.00335 mol of I⁻. Since each molecule of MgI₂ produces two I⁻ ions, we divide 0.00335 by 2 to determine the moles of MgI₂, giving us 0.001675 mol.
Consequently, the quantity of MgI₂ to be added is:
Weight of MgI₂ = 0.001675 mol x 278 g/mol = 0.4656 g = 465.6 mg
Answer:
0.133
Explanation:
The reaction that occurs between KIO3 and KI in an acidic medium is described as
IO3⁻ +5I⁻ +6h⁺ → 3I₂ + 3H₂O
I₂ subsequently reacts with sodium thiosulfate
NaS₂O₃ → 2Na⁺ + S₂O₃²⁻
The overall reaction can be summarized as
IO⁻₃ + 6H⁺ + 6S₂O₃³⁻ → I⁻ + 3S₄O₆²⁻ + 3H₂O
The mole of KIO₃
is computed using molarity multiplied by volume
which equals 0.00002mol
One mole of KIO₃ reacts with 6 moles of S₂O₃²⁻
which gives 2x6x10⁻⁵
= 0.00012 mol
The volume is 0.90 ml
1 ml equals 0.001L
0.90ML is 0.0009L
To find concentration,
molarity/volume
= 0.00012/0.0009
= 0.133m
