Answer:
5
Explanation:
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Answer: -
Substance A is carbon dioxide and Substance B is oxygen.
Explanation: -
Photosynthesis reaction involves the process of conversion of light energy of the sun into chemical energy by the green chlorophyll found in plants leaves.
The chemical equation for the process is
6 CO₂ +6 H₂O → C₆H₁₂O₆ + 6O₂
As we can see Carbon dioxide CO₂ reacts with water H₂O to form glucose. Oxygen is the gaseous product formed.
Thus Substance A is carbon dioxide and Substance B is oxygen.
Answer:
A part.
Explanation:
Because the reactants must be the exact same as the the products.
Given :
A 10.99 g sample of NaBr contains 22.34% Na by mass.
To Find :
How many grams of sodium does a 9.77g sample of sodium bromine contain.
Solution :
By law of constant composition , in any given chemical compound, the elements always combine in the same proportion with each other.
Therefore , percentage of Na by mass in NaBr will be same for every amount .
Percentage of Na in 9.77 g NaBr is 22.34 % too .
Gram of Na = 
.
Hence , this is the required solution .
Answer:
a) 210 mL of 95% ethanol
b) 75 mL of water
Explanation:
a) We can use the dilution equation to solve this problem. C₁ and V₁ are the concentration and volume of the stock solution, respectively, while C₂ and V₂ are the concentration and volume of the diluted solution.
C₁V₁ = C₂V₂
We want to find V₁, the volume of ethanol stock we need to dilute to prepare the final solution:
V₁ = (C₂V₂) / C₁
The concentrations are represented in percentages. We substitute in the known values to calculate V₁. The units cancel to leave us with units of mL.
V₁ = (C₂V₂) / C₁ = (70%)(285mL) / (95%) = 210 mL
b) The final solution volume is 285 mL and we have added 210 mL of ethanol, so the remaining volume is from the water that we add:
(285 mL - 210 mL) = 75 mL
