why does every human measurement have uncertainty associated with it? Why must we manage the uncertainty during calculations?

1 answer:

3 0

Because there are many numbers of the human measurement . we must manage the uncertainly doing calculations because we can know what we are calculating.

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A container holds 15.0 g of phosphorous gas at a pressure of 2.0 atm and a temperature of 20.0 Celsius. What is the density of t

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Density is a value for mass, such as kg, divided by a value for volume, such as m3. Density is a physical property of a substance that represents the mass of that substance per unit volume. We calculate as follows:

PV = nRT
PV = mRT/ Molar mass
m/V = P(molar mass)/RT
Density = P(molar mass)/RT
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In a container containing co, h2, and o2, what is the mole fraction of co if the h2 mole fraction is 0.22 and the o2 mole fracti

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Thank you for posting your question here at brainly. The mole fraction of co if the h2 mole fraction is 0.22 and the o2 mole fraction is 0.58 is 0.20, below is the solution:

mole fraction CO + mole fraction H2 + mole fraction O2 = 1

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The combustion of propane occurs when propane interacts with oxygen gas to produce water and carbon dioxide in the following rea

gtnhenbr [62]

Answer:

20 atm

Explanation:

1) Data:

a) n = 2 moles

b) T = 373 K

c) V = 2.5 liter

d) P = ?

2) Chemical principles and formula

You need to calculate the pressure of the propane gas in the mixture before reacting. So, you can apply the partial pressure principle which states that each gas exerts a pressure as if it occupies the entire volume.

Thus, you just have to use the ideal gas equation: PV = nRT

3) Solution:

PV = nRT ⇒ P = nRT / V

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Since the number of moles are reported with one significant figure, you must round your answer to one significant figure, and that is 20 atm (20 is closer to 24.5 than to 30).

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This method of quantitative determination of percent purity is titrimetric reactions. These reactions most commonly involve neutralization reactions between an acid and a base. Then, we look at the neutralization reaction:

H₂C₂O₄ + 2 NaOH ⇒ Na₂C₂O₄ + 2 H₂O

So, we do the stoichiometric calculations. The important data we should know is the molar mass of oxalic acid which is equal to 90 g/mol.

(0.2283 mol/L NaOH * 0.3798 L * 1 mol H₂C₂O₄/ 2mol NaOH * 90 g/mol H₂C₂O₄) ÷ 0.7984 g *100%
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