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
kozerog [31]
2 years ago
9

Which of these is an accurate source of evidence for an investigation?

Chemistry
1 answer:
Feliz [49]2 years ago
4 0

Answer:

observations

Explanation:

You might be interested in
Percent concentration is one of the most common and basic concentration measurement used by general public. true or false?
Aleksandr [31]

Answer:

  • <u>TRUE:</u> <em>Percent concentration is one of the most common and basic concentration measurement used by general public</em>

Explanation:

In chemistry there are many <em>concentration measurements</em> used to describe the mixtures. Some of them are, percent, molarity, molality, and molar fraction, among others.

Percent concentration is a popular one because it is commonly understood and used by the non specialist people, i.e. general public.

The percent concentration of a component is defined as: (amount of component in the mixture / amount of mixture) × 100.

The amounts may be measured in mass units (e.g grams) or volume units (e.g. mililiters).

For solutions, mass percent concentration is:

  • % = (mass of solute / mass of solution) × 100.

And voluem percen contration is:

  • % = (volume of solute / volume of solution) × 100

Since percentage is used in many profesional and personal activities, most persons use it.

For example, rubbing alcohol, that everyone buys in pharmacies, is 70%; vinager, used in the food, is acetic acid at 5% - 8%.

5 0
2 years ago
How are elements with atomic masses greater than Uranium’s made?
JulsSmile [24]
Atoms heavier that uranium do not exist in nature.they must be synthesized in a particle accelerator.
7 0
3 years ago
Does adding milk impact the health benefits of the tea? Use your understanding from this unit about solutions and food chemistry
mezya [45]
Yes, it mixes it and has vitamins in the tea.
5 0
3 years ago
The acid dissociation constant Ka of boric acid (H3BO3) is 5.8 times 10^-10. Calculate the pH of a 4.4 M solution of boric acid.
madam [21]

Answer: The pH of a 4.4 M solution of boric acid is 4.3

Explanation:

H_3BO_3\rightarrow H^+H_2BO_3^-

at t=0  cM              0             0

at eqm c-c\alpha        c\alpha          c\alpha  

So dissociation constant will be:

K_a=\frac{(c\alpha)^{2}}{c-c\alpha}

Give c= 4.4 M and \alpha = ?

K_a=5.8\times 10^{-10}

Putting in the values we get:

5.8\times 10^{-10}=\frac{(4.4\times \alpha)^2}{(4.4-4.4\times \alpha)}

(\alpha)=0.000011

[H^+]=c\times \alpha

[H^+]=4.4\times 0.000011=4.8\times 10^{-5}M

Also pH=-log[H^+]

pH=-log[4.8\times 10^{-5}]=4.3

Thus pH of a 4.4 M H_3BO_3 solution is 4.3

3 0
3 years ago
A chemist adds 485 mL of a 0.0025 mol/L calcium sulfate solution to a reaction flask. Calculate the mass in grams of calcium sul
viva [34]

Answer : The mass in grams of calcium sulfate is 0.16 grams.

Explanation :

Molarity : It is defined as the number of moles of solute present in one litre of solution.

Formula used :

Molarity=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution}}

Solute is, CaSO_4

Given:

Molarity of CaSO_4 = 0.0025 mol/L

Molar mass of CaSO_4 = 136 g/mole

Volume of solution = 485 mL

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

0.0025=\frac{\text{Mass of }CaSO_4\times 1000}{136\times 485}

\text{Mass of }CaSO_4=0.16g

Thus, the mass in grams of calcium sulfate is 0.16 grams.

6 0
3 years ago
Other questions:
  • In general, when a substance changes from a solid to a liquid,
    14·1 answer
  • Use the changes in oxidation numbers to identify which atoms are oxidized and which are reduced in each reaction.
    14·1 answer
  • The most common shape for a galaxy is ______.
    5·1 answer
  • Carbon can bond to itself to form which of the following?
    6·1 answer
  • How much volume (in cm3) is gained by a person who gains 11.1 lbs of pure fat?
    12·1 answer
  • Which factors are needed to determine the amount of heat absorbed by an aluminum cube after it is warmed?
    5·1 answer
  • I WILL RATE BRAINLIEST I JUST NEED HELP!!!!
    6·2 answers
  • how can you find the common denominator and least commom denominator?? Help and thx i accedentaly clicked on the wrong subject
    14·1 answer
  • In which main energy level does the 'd' sublevel first appear? K (first main energy level) L (second main energy level) M (third
    7·1 answer
  • Write short notes on different planet of the solar system​
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!