Answer:
B and D could be true
Explanation:
A volume of sodium hydroxide less than expected could occurs for two reasons:
The real concentration of sodium hydroxide was higher than expected or the amount of vinegar added was less than expected:
A. The sodium hydroxide solution had been allowed to stand exposed to the air for a long time prior to the titration. FALSE. A long expose to the air decreases concentration of the NaOH.
B. The volumetric flask used to prepare the diluted vinegar solution was rinsed with water prior to use. TRUE. You add a less amount of vinegar doing you require less amount of NaOH than expected.
C. The burette used to deliver the sodium hydroxide solution was rinsed with water prior to use. FALSE. Thus, you add a less amount of NaOH than expected. To explain the matter, you add more NaOH than expected.
D. The pipette used to deliver the vinegar solution was rinsed with water prior to use. TRUE. Again, you are adding a less amount of Vinegar than expected doing the necessary NaOH during titration less than expected
Answer:
Explanation:
Azimuthal maps projection is the easiest for plotting travel by airplane because Azimuthal maps make the UV plane to be tangent to the globe and it's make the directions from the center of projections to be correct and accurate to any other points , likewise circles are also projected directly to the straight lines on the plane. And this is because Any line that is normally drawn through the tangent point give distance correctly and accurately.
Answer:
The richer source of calcium is fluorite.
Explanation:
Percentage of element in compound :
1. Dolomite is a carbonate of magnesium and calcium:
Given mass of dolomite = 7.81 g
Mass of calcium present in given mass of dolomite = 1.70 g
Percentage of calcium in Dolomite:
2. Fluorite is a mineral of calcium and fluorine:
Given mass of fluorite = 2.76 g
Mass of fluorine present in given mass of fluorite = 1.34 g
Percentage of fluorine in fluorite :
Percentage of calcium in fluorite = 100% - 48.55 % = 51.45%
Percentage of calcium in fluorite > Percentage of calcium in Dolomite
51.455 > 21.77%
So, the richer source of calcium is fluorite.
Answer:
4.4 moles of water
Explanation:
Propane is C3H8. Is the chemical equation, you wrote C2H8 which is wrong. Type everything properly and give a check before finally posting the question.
The chemical equation that is given, is not properly balanced. The BALANCED equation would be
C3H8 + 5O2 → 3CO2 + 4H2O
From this balanced chemical equation, we see that 5 moles of oxygen produce 4 moles of water.
5 moles of Oxygen → 4 moles of water
1mole of oxygen → 
moles of water
5.5 moles of oxygen → ( × 5.5) moles of water = 4.4 moles of water
∴ The reaction of 5.5 mol of O2 will produce <u>4.4</u> mol of H2O. [Answer:]
