Answer:
70%
Explanation:
To find the percent yield, you need to (1) convert grams HCl to moles (via molar mass from periodic table), then (2) convert moles HCl to moles H₂ (via mole-to-mole ratio from equation), then (3) calculate the percent yield H₂ (via percent yield equation).
Zn (s) + 2 HCl (aq) --> ZnCl₂ (aq) + 1 H₂ (g)
Molar Mass (HCl): 1.008 g/mole + 35.45 g/mole
Molar Mass (HCl) = 36.458 g/mole
125 g HCl 1 mole HCl 1 mole H₂
--------------- x ------------------ x ------------------ = 1.7 moles H₂
36.458 g 2 moles HCl
(actual yield / theoretical yield) x 100% = percent yield
theoretical/calculated yield = 1.7 moles H₂
actual yield = 1.2 moles H₂
(1.2 moles H₂ / 1.7 moles H₂) x 100% = 71%
Therefore, the best percent yield of hydrogen produced is 70%.
2.4 × 10⁻² is the pH of a solution
What is the short definition of pH?
- The pH scale determines how acidic or basic water is. The range is 0 to 14, with 7 representing neutrality. Acidity is indicated by pH values below 7, whereas baseness is shown by pH values above 7.
- In reality, pH is a measurement of the proportion of free hydrogen and hydroxyl ions in water.
Equation representing the i onization of Na₃PO₄ is as fallow
Na₃PO₄ → PO₄³⁻ + 3Na⁺
Concentration of Na₃PO₄ = 
Since 1 mol of Na₃PO₄ forms 1 mol of PO₄³⁻ [ PO₄³⁻ ] = [ Na₃PO₄ ] = 0.164 M
Equation representing the i onization of HPO²⁻₄ is as fallow
HPO²⁻₄ → PO₄³⁻ + H⁺
Acidionization constant Ka₃ of HPO²⁻₄ = 4. 17 × 10⁻¹³
Baseionization constant Kb₃ of PO₄³⁻ = Ka₃/ Kb₃
= 1 .0 × 10⁻¹⁴/ 4. 17 × 10⁻¹³ = 2.4 × 10⁻²
Learn more about pH
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Lipids are insoluble in water and they produce twice as more energy as carbohydrates.
To determine the mass, you need to know the molecular weight of the c8h10n4o2 . The molecular weight of <span>c8h10n4o2 would be: 8*12 + 10*1 + 4*14 + 2*16= 194g/mol.
To convert the number of molecules into moles, you need to divide it with 6.02 * 10^23. The calculation of the mass of </span>c8h10n4o2 would be:
(7.20×10^20 molecules) /(6.02 * 10^23 molecule/mol) * 194g/mol= 232 * 10^-3 grams= 0.232 grams
The answer would be C) Observe and ask questions because if we do process of elimination we see that drawing conclusions is NOT the first step, forming a hypothesis and illustrating the process is part of the method, but NOT the first step.
