Answer:
The correct answer is 25 mL graduated cylinder (it should be used in all the cases)
Explanation:
In order to measure 25.00 ml sample of a solution it should be used a 25 mL graduated cylinder, as it is previously and properly calibrated. The other laboratory glassware, beaker and erlenmeyer, have graduations which are approximate, so they are used when exact volumes are not needed.
ii) graduated cylinder has the least uncertainly. It is more accurate than a beaker or erlenmeyer (to within 1%)
iii) A 25 mL graduated cylinder should be used because it is the most accurate lab glassware (between those were mentioned: beaker, erlenmeyer).
Answer:
14 mol e⁻
Explanation:
Step 1: Write the balanced half-reaction for the reduction of permanganate to manganese
8 H⁺(aq) + 7 e⁻ + MnO₄⁻(aq) ⇒ Mn(s) + 4 H₂O(l)
Step 2: Calculate the moles corresponding to 110 g of manganese
The molar mass of Mn is 55 g/mol.
110 g × 1 mol/55 g = 2 mol
Step 3: Calculate the number of moles of electrons needed to produce 2 moles of Mn
According to the half-reaction, 7 moles of electrons are required to produce 1 mole of Mn.
2 mol Mn × 7 mol e⁻/1 mol Mn = 14 mol e⁻
Hydrochloric acid and sodium hydroxide
HCl + NaOh ----> NaCl + H2O
The most stable isotope would be lead-82.
Formula units are there in 212 grams of MgCl₂ are 830.56
Formula is the empirical of any ionic or covalent network solid compound used as an independent entity for stoichiometric calculations and it is the lowest whole number ratio of ions represented in an ionic compound
Here given data is
MgCl₂ = 212 grams
1 mole of magnesium chloride has mass = 95.211 gram and contains 6.022×10²³formula units of magnesium chloride
Here 212 grams×6.022×10²³form unit of MgCl₂/95.211 gram = 830.56
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