All categories

2 years ago

Why do we need to calibrate equipment

Chemistry

1 answer:

Vlad1618 [11]2 years ago

3 0

Answer:

to be precise in the calculations

Explanation: for example your cell phone has a gps inside it, the gps is responsible for providing direction data like a compass, if the equipment is not calibrated, the gps will not find the correct direction.

You might be interested in

Calculate the initial rate for the formation of c at 25 ∘c, if [a]=0.50m and [b]=0.075m

Nataly_w [17]

The rate of formation of a product depends on the the concentrations of the reactants in a variable way.

If two products, call them A and B react together to form product C, a general equation for the formation of C has the form:

rate = k*[A]^m * [B]^n

Where the symbol [ ] is the concentration of each compound.

Then, plus the concentrations of compounds A and B you need k, m and n.

Normally you run controled trials in lab which permit to calculate k, m and n .

Here the data obtained in the lab are:

Trial [A] [B] Rate 
 (M) (M) (M/s) 
1 0.50 0.010 3.0×10−3 
2 0.50 0.020 6.0×10−3 
3 1.00 0 .010 1.2×10−2

Given that for trials 1 and 2 [A] is the same you can use those values to find n, in this way

rate 1 = 3.0 * 10^ -3 = k [A1]^m * [B1]^n

rate 2 = 6.0*10^-3 = k [A2]^m * [B2]^n

divide rate / rate 1 => 2 = [B1]^n / [B2]^n

[B1] = 0.010 and [B2] = 0.020 =>

6.0 / 3.0 =( 0.020 / 0.010)^n =>

2 = 2^n => n = 1

Given that for data 1 and 3 [B] is the same, you use those data to find m

rate 3 / rate 1 = 12 / 3.0 = (1.0)^m / (0.5)^m =>

4 = 2^m => m = 2

Now use any of the data to find k

With the first trial: rate = 3*10^-3 m/s = k (0.5)^2 * (0.1) =>

k = 3.0*10^-3 m/s / 0.025 m^3 = 0.12 m^-2 s^-1

Now that you have k, m and n you can use the formula of the rate with the concentrations given

rate = k[A]^2*[B] = 0.12 m^-2 s^-1 * (0.50m)^2 * (0.075m) = 0.0045 m/s = 4.5*10^=3 m/s

Answer: 4.5 * 10^-3 m/s

8 0

3 years ago

Read 2 more answers

What are the observed results of an experiment that occur from changes in independent variable

gayaneshka [121]

I believe it is the dependent variable b/c it is the thing(s) that is been observe or measure

3 0

3 years ago

The concentration of hydrogen peroxide solution can be determined by

max2010maxim [7]

The question is incomplete, the complete reaction equation is;

The concentration of a hydrogen peroxide solution can be determined by titration

with acidified potassium manganate(VII) solution. In this reaction the hydrogen

peroxide is oxidised to oxygen gas.

A 5.00 cm3 sample of the hydrogen peroxide solution was added to a volumetric flask

and made up to 250 cm3 of aqueous solution. A 25.0 cm3 sample of this diluted

solution was acidified and reacted completely with 24.35 cm3 of 0.0187 mol dm–3

potassium manganate(VII) solution.

Write an equation for the reaction between acidified potassium manganate(VII)

solution and hydrogen peroxide.

Use this equation and the results given to calculate a value for the concentration,

in mol dm–3, of the original hydrogen peroxide solution.

(If you have been unable to write an equation for this reaction you may assume that

3 mol of KMnO4 react with 7 mol of H2O2. This is not the correct reacting ratio.)

Answer:

2.275 M

Explanation:

The equation of the reaction is;

2 MnO4^-(aq) + 16 H^+(aq) + 5H2O2(aq) -------> 2Mn^+(aq) + 10H^+ (aq) + 8H2O(l)

Let;

CA= concentration of MnO4^- = 0.0187 mol dm–3

CB = concentration of H2O2 = ?

VA = volume of MnO4^- = 24.35 cm3

VB = volume of H2O2 = 25.0 cm3

NA = number of moles of MnO4^- = 2

NB = number of moles of H2O2 = 5

From;

CAVA/CBVB = NA/NB

CAVANB = CBVBNA

CB = CAVANB/VBNA

CB = 0.0187 * 24.35 * 5/25.0 * 2

CB = 0.0455 M

Since

C1V1 = C2V2

C1 = initial concentration of H2O2 solution = ?

V1 = initial volume of H2O2 solution = 5.0 cm3

C2 = final concentration of H2O2 solution= 0.0455 M

V2 = final volume of H2O2 solution = 250 cm3

C1 = C2V2/V1

C1 = 0.0455 * 250/5

C1 = 2.275 M

8 0

3 years ago

C2H4O2 + NaC2H3O2 + H2O + CO2 list the reactants in this chemical reaction

lisabon 2012 [21]

Answer:

C₂H₄O₂ and NaC₂H₃O₂ are reactants.

Explanation:

Word equation:

Acetic acid + sodium acetate → sodium diacetate

Chemical equation:

C₂H₄O₂ + NaC₂H₃O₂ → C₄H₇NaO₄

This is a synthesis reaction in which simple reactants combine to form complex product.

This is also balanced chemical equation because there are equal number of atoms of all elements on both side of equation. Thus it follow the law of conservation of mass.

Law of conservation of mass:

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

7 0

3 years ago

You place a carrot in salt water for 24 hours. What do you observe about the carrot at the end of that time? Choose the two corr

natka813 [3]

Answer:

A & E

Explanation:

Salt water is a hypertonic solution, meaning it extracts water from whatever is placed in it. When a carrot loses water, it will most likely shrivel up and become limp.

8 0

3 years ago

Read 2 more answers

Why do we need to calibrate equipment​

Why do we need to calibrate equipment