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
igomit [66]
3 years ago
15

Thea is doing a chemistry experiment. The instructions say she needs to use pure water. Hamza offer her a bottle labelled “100%

Pure Spring Water”. Suggest why this water is unlikely to be suitable for the experiment [2]
A scientist is comparing 2 samples of the same compound. One is pure and the other is impure. The compound is a solid at room temperature. Explain how the scientist could tell which is the pure compound. [2]

The melting point of pure asprin is 136oC. The melting point of a sample of asprin is measured as being between 128 – 132oC. Give two reasons that suggest the sample is not pure asprin. [2]
Gunpowder is a formulation of potassium nitrate, charcoal and sulphur in the ratio 15 : 3 : 2
What is meant by the term “formulation” [2]
Calculate the mass of charcoal in 40g of gunpowder [1]
if you can just give me hints that would be great
Chemistry
1 answer:
Diano4ka-milaya [45]3 years ago
5 0
How is this going to help us in life wat the fawk
You might be interested in
How many moles of aluminum oxide (Al2O3) can be produced from 12.8 moles of oxygen gas (02)
zhannawk [14.2K]

Answer:

Theoretical Yield

Percent yield

Example stoichiometry problem

How much oxygen can be prepared from 12.25 g KClO3 . (Use molar mass KClO3 = 122.5 g.)

Most stoichiometry problems can be solved using the following steps.

Step 1.

Write and balance the equation for the decomposition of KClO3 with heat (∆). 2KClO3 + ∆ → 2KCl + 3O2

Step 2.

Convert what you have (in this case g KClO3) to moles.

# moles = grams/molar mass = 12.25 g /122.5 = 0.100 mole KClO3.

Step 3.

Using the coefficients in the balanced equation, convert moles of what you have (moles KClO3) to moles of what you want (in this case moles oxygen).

0.100 mol KClO3 x (3 moles O2/2 moles KClO3) = 0.100 x (3/2) = 0.150 mole O2.

Step 4.

Convert moles from step 3 to grams.

moles x molar mass = grams

0.150 mole O2 x (32.0 g O2/mole O2) = 4.80 g O2 produced from 12.25 g KClO3. This is the theoretical yield. If the ACTUAL yield is 4.20 grams, calculate percent yield. Percent yield = (actual yield/theoretical yield) x 100 = (4.20/4.80) x 100 = 87.5% yield

NOTE: In step 1, moles can be obtained other ways; in step 4 moles can be converted to other units.

a. For solutions, M x L = moles (or mL x M = millimoles).

b. For gases, L/22.4 = moles

4 0
3 years ago
Why are people against saving the ozone layer?
nalin [4]
Because they don't care and think the ozone layer is fine.
3 0
2 years ago
How many phases are in a homogeneous mixture??
Mars2501 [29]
Technically there is only one phase unless you account for a solution where you have a pure liquid with something dissolved in it. Unless you count aqueous as a phase which is just dissolved. Since you are in high school the answer you are looking for is one.  <span />
7 0
3 years ago
Read 2 more answers
Plz help this is due today
vazorg [7]

Answer:

Explanation:

-

7 0
2 years ago
Read 2 more answers
How many moles of HNO3 are present if 4.90×10−2 mol of Ba(OH)2 was needed to neutralize the acid solution?
Amiraneli [1.4K]

Answer:

0.098 moles

Explanation:

Let y represent the number of moles present

1 mole of Ba(OH)₂ contains 2 moles of OH- ions.

Hence, 0.049 moles of Ba(OH)2 contains y moles of OH- ions.

To get the y moles, we then do cross multiplication

1 mole *  y mole = 2 moles * 0.049 mole

y mole = 2 * 0.049 / 1

y mole =  0.098 moles of OH- ions.

1 mole of OH- can neutralize 1 mole of H+

Therefore, 0.098 moles of HNO₃ are present.

3 0
3 years ago
Other questions:
  • Changing the number of protons in an atom makes<br><br> A. an ion<br> B. an isotope
    10·1 answer
  • What’s the answer for #9
    6·1 answer
  • Which is the least reliable method for identifying a mineral
    5·2 answers
  • Chemical equations must be balanced to satisfy ...?
    7·2 answers
  • What mass of oxygen is needed to combust and produced 6.4 moles of carbon dioxide gas?
    15·1 answer
  • If temperature is kept constant and the volume of a gas is doubled, what will happen to the pressure?
    6·1 answer
  • To what volume should you dilute 50.0 ml of 12 m hno3 solution to obtain a 0.100 m hno3 solution?
    6·1 answer
  • Name: _________________ Temperature o fwater_25_degreecent.YOU MUST SHOW ALL CALCULATIONS TO RECEIVE CREDIT FOR THEM! DATA ANALY
    5·1 answer
  • Convert from moles to particles 6.02x1023 particles 1 mole Question 2. 2.7 moles of lithium Question 3. 1.8 moles of sodium chlo
    5·1 answer
  • What must happen for an electron to return to its original energy level from a higher energy level?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!