All categories

3 years ago

Which of the following has/have mistakes in the expression of the value/uncertainty?

Chemistry

1 answer:

DerKrebs [107]3 years ago

7 0

The reported uncertainty of a measurement cannot be greater than the accuracy of the measurement.

In this case the refractive index of glass = 1.5321 +/- 0.00125

Here the measured value = 1.5321 which is reported upto 4 decimal places. However, the uncertainty = 0.00125 has been reported upto 5 decimal places which is inaccurate.

Instead, the refractive index can be reported as: 1.5321 +/- 0.0013

Ans 3)

You might be interested in

Where does radioactivity come from?

Aleks04 [339]

Radioactivity comes from unstable atoms of certain elements. Radioactivity consists of alpha radiation (2 protons and 2 neutrons), beta radiation (1 electron), or gamma radiation (Electromagnetic photons).

8 0

3 years ago

Read 2 more answers

The sp of pbbr2 is 6. 60×10−6. what is the molar solubility of pbbr2 in pure water?

Inessa05 [86]

Ksp of PbBr₂ is 6.60 × 10⁻⁶. The molar solubility of PbBr₂ in pure water is 0.0118M.

Ksp or Solubility Product Constant is an equilibrium constant for the dissociation in an aqueous solution.

Molar solubility (S) is the concentration of the dissolved substance in a solution that is saturated.

Let the molar solubility be S upon dissociation.

PbBr₂ or Lead Bromide dissociates in pure water as follows:

PbBr₂ ----------> Pb⁺² + Br⁻

S 2S

Ksp = [Pb⁺²] [ Br⁻]

Ksp = (S) (2S)²

Ksp = 4S³

6.60 × 10⁻⁶ = 4S³

S = 0.0118M

Hence, the Molar solubility S is 0.0118M.

Learn more about Molar solubility here, brainly.com/question/16243859

#SPJ4

6 0

2 years ago

When 0.250 moles of KCl are added to 200.0 g of water in a constant pressure calorimeter a temperature change is observed. Given

777dan777 [17]

Explanation:

Upon dissolution of KCl heat is generated and temperature of the solution raises.

Therefore, heat generated by dissolving 0.25 moles of KCl will be as follows.

$17.24 kJ/mol \times 0.25 mol$

= 4.31 kJ

or, = 4310 J (as 1 kJ = 1000 J)

Mass of solution will be the sum of mass of water and mass of KCl.

Mass of Solution = mass of water + (no. of moles of KCl × molar mass)

= 200 g + $(0.25 mol \times 54.5 g/mol)$

= 200 g + 13.625 g

= 213.625 g

Relation between heat, mass and change in temperature is as follows.

Q = $mC \Delta T$

where, C = specific heat of water = $4.184 J/g^{o}C$

Therefore, putting the given values into the above formula as follows.

Q = $mC \Delta T$

4310 J = $213.625 g \times 4.184 J/g^{o}C \times \Delta T$

$\Delta T = 4.82^{o}C$

Thus, we can conclude that rise in temperature will be $4.82^{o}C$ .

6 0

3 years ago

The equation to calculate mean rate of reaction g/s

tatyana61 [14]

amount of product formed or amount of reactants used / time

8 0

3 years ago

What happens to blood cells if there is too much sugar in the blood stream?

Crank

Hyperglycemia is when blood sugar levels are always higher, only happens when insulin doesn’t respond properly. Without insulin glucose can’t get into cells and so it builds up in the bloodstream.

8 0

2 years ago