Answer:
24.525 g of sulfuric acid.
Explanation:
Hello,
Normality (units of eq/L) is defined as:
Since the sulfuric acid is the solute, and we already have the volume of the solution (500 mL) but we need it in liters (0.5 L, just divide into 1000), the equivalent grams of solute are given by:
Now, since the sulfuric acid is diprotic (2 hydrogen atoms in its formula) 1 mole of sulfuric acid has 2 equivalent grams of sulfuric acid, so the mole-mass relationship is developed to find its required mass as follows:
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Answer:
3S₈ + 28Br₂ => 8S₃Br₇
Explanation:
Start with either sulfur (S) or bromine (Br) and balance ...
3S₈ + Br₂ => 8S₃Br₇ or S₈ + 7/2Br₂ => S₃Br₇
Balance the remaining reactant ...
3S₈ + 56/2Br₂ => 8S₃Br₇
Remove fractions by multiplying by the fraction's denominator
2(3S₈ + 56/2Br₂ => 8S₃Br₇) => 6S₈ + 56Br₂ => 16S₃Br₇
Reduce to smallest whole number ratio => standard equation at STP ...
3S₈ + 28Br₂ => 8S₃Br₇
Answer:
In the third tube, the concentration is 0.16 ug/mL
Explanation:
In the first step, the solution is diluted by 5. Then, the concentration will be
20 ug/mL / 5 = 4 ug/mL
Then, in the second step this 4 ug / ml solution is diluted by a factor of five again:
4 ug /ml / 5 = 0.8 ug/mL
This solution is then diluted again by 5 and the concentration in the third tube will be then:
0.8 ug/mL / 5 = <u>0.16 ug/mL </u>
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Another way to calculate this is to divide the original concentration by the dilution factor ( 5 in this case) elevated to the number of dilutions. In this case:
Concentration in the third tube = 20 ug/mL / 5³ = 0.16 ug/mL
Answer:
305 g of CO₂
3.77 × 10⁵ kJ
Explanation:
Let's consider the global reaction for photosynthesis.
6 CO₂(g) + 6 H₂O(l) → C₆H₁₂O₆(g) + 6 O₂(g) ΔHrxn = 2802.8 kJ
<em>A 1.70 lb sweet potato is approximately 73% water by mass. If the remaining mass is made up of carbohydrates derived from glucose (MW = 180.156 g/mol), how much carbon dioxide (MW = 44.01 g/mol) was needed to grow this sweet potato?</em>
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Let's consider the following relations:
- The potato is 100%-73%=27% glucose by mass.
- 1 lb = 453.59 g.
- 6 moles of CO₂ produce 1 mole of glucose.
- The molar mass of glucose is 180.156 g/mol.
- The molar mass of carbon dioxide is 44.01 g/mol.
Then, for a 1.70 lb potato:
<em>How much light energy does it take to grow the 1.70 lb. sweet potato if the efficiency of photosynthesis is 0.86%?</em>
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According to the enthalpy of the reaction, 2802.8 kJ are required to produce 1 mole of glucose. Then, for a 1.70 lb potato:
Identify each element found in the equation. The number of atoms of each type of atom must be the same on each side of the equation once it has been balanced.
What is the net charge on each side of the equation? The net charge must be the same on each side of the equation once it has been balanced.
If possible, start with an element found in one compound on each side of the equation. Change the coefficients (the numbers in front of the compound or molecule) so that the number of atoms of the element is the same on each side of the equation. Remember, to balance an equation, you change the coefficients, not the subscripts in the formulas.
Once you have balanced one element, do the same thing with another element. Proceed until all elements have been balanced. It's easiest to leave elements found in pure form for last.
Check your work to make certain the charge on both sides of the equation is also balanced.
