1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
skelet666 [1.2K]
3 years ago
12

A standard 10.00 g mass is weighed on an analytical balance 100 times. The average and standard deviation obtained gives 10.12 ±

0.03 g. A calibration service is called. After the balance is recalibrated, the new measurements show 10.00 ± 0.03 g. Did the recalibration result in improved accuracy or precision?
Chemistry
1 answer:
Mekhanik [1.2K]3 years ago
5 0

Answer:

There was an improvement in accuracy. There was no change in precision.

Explanation:

<em>The average mass after recalibration is closer to the mass of the standard, </em>so the recalibration improved the accuracy<em> </em>(the measurement is closer to an accepted 'true' value).

The standard deviation did not change, so the precision (or how disperse the measurements are) was not affected.

You might be interested in
What was the purpose of letting the transformed cells sit in LB for a few minutes before spreading them onto the plates?
AlekseyPX
I think c ... C this is the correct
8 0
3 years ago
If molecule dissociates in water what does it do
natita [175]
It either forms a base or an acid...I think that's the answer you're looking for
4 0
3 years ago
Find the enthalpy of neutralization of HCl and NaOH. 137 cm3 of 2.6 mol dm-3 hydrochloric acid was neutralized by 137 cm3 of 2.6
liraira [26]

Answer : The correct option is, (D) 89.39 KJ/mole

Explanation :

First we have to calculate the moles of HCl and NaOH.

\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole

\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole

The balanced chemical reaction will be,

HCl+NaOH\rightarrow NaCl+H_2O

From the balanced reaction we conclude that,

As, 1 mole of HCl neutralizes by 1 mole of NaOH

So, 0.3562 mole of HCl neutralizes by 0.3562 mole of NaOH

Thus, the number of neutralized moles = 0.3562 mole

Now we have to calculate the mass of water.

As we know that the density of water is 1 g/ml. So, the mass of water will be:

The volume of water = 137ml+137ml=274ml

\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1g/ml\times 274ml=274g

Now we have to calculate the heat absorbed during the reaction.

q=m\times c\times (T_{final}-T_{initial})

where,

q = heat absorbed = ?

c = specific heat of water = 4.18J/g^oC

m = mass of water = 274 g

T_{final} = final temperature of water = 325.8 K

T_{initial} = initial temperature of metal = 298 K

Now put all the given values in the above formula, we get:

q=274g\times 4.18J/g^oC\times (325.8-298)K

q=31839.896J=31.84KJ

Thus, the heat released during the neutralization = -31.84 KJ

Now we have to calculate the enthalpy of neutralization.

\Delta H=\frac{q}{n}

where,

\Delta H = enthalpy of neutralization = ?

q = heat released = -31.84 KJ

n = number of moles used in neutralization = 0.3562 mole

\Delta H=\frac{-31.84KJ}{0.3562mole}=-89.39KJ/mole

The negative sign indicate the heat released during the reaction.

Therefore, the enthalpy of neutralization is, 89.39 KJ/mole

3 0
3 years ago
As the energy of the molecules increases, the motion of the molecules _______.
Alexus [3.1K]

Answer:

the motion of molecules increases

6 0
2 years ago
What is the role of neutrons in an atom??
Colt1911 [192]
They're only found in the nucleus and play an important role in keeping the atom stable because they carry a negative charge to counteract the proton's positive charge. 
7 0
3 years ago
Read 2 more answers
Other questions:
  • The energy level has the lowest energy.
    14·1 answer
  • Why is the arm often described as a sort of lever?
    12·2 answers
  • Draw the structure of a compound with molecular c8h14 that reacts with one equivalent of h2 over pd/c to form a meso compound. d
    8·1 answer
  • Scientists use the chemical and physical properties of matter to differentiate substances. Which of the following is a chemical
    7·2 answers
  • Which property of metals is the result of light reflecting off the electrons?
    14·1 answer
  • I am one percent away from failing. I just need help. No false answers
    8·1 answer
  • If the gas begins at the conditions described in Trial 1, determine the volume of the gas at STP.
    5·1 answer
  • Can someone help a dude out im stuck on this question
    10·1 answer
  • 0.6 sample an unknown organic acid found in muscle cells is burned in air and found to contain 0.24g of carbon, 0.04g of hydroge
    14·1 answer
  • HELP, THANKS
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!