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
alina1380 [7]
3 years ago
6

Read the descriptions below of two substances and an experiment on each. Decide whether the result of the experiment tells you t

he substance is a pure substance or a mixture, if you can.
Sample A is of a coarse grey powder with a faint unpleasant smell. of the powder is put into a funnel lined with a sheet of thick paper. Distilled water is poured slowly over the powder. Most of the powder disappears, but of a gritty black sand-like material is left on the surface of the paper. Pouring more water over the black material doesn't change how much of it there is.

Sample B is a solid yellow cube with a total mass of 50.0 g. The cube is put into a beaker filled with 250. mL of water. The cube collapses into a small pile of orange powder at the bottom of the beaker. When this powder is filtered out, dried and weighed, it has a total mass of 29.9 g. If the experiment is repeated with 500. mL of water, the powder that's left over has a mass of 10.0 g.
Chemistry
1 answer:
Lelu [443]3 years ago
8 0

Answer:

Sample A - mixture

Sample B- Mixture

Explanation:

Looking at sample A, we can see that as water was poured over sample A, the sample was separated into its components as the powder disappeared leaving behind a gritty black sand-like material on the surface of the paper. A separation of the mixture has taken place.

In sample B, we can clearly see that it is a mixture because the amount of solid recovered is much less than the total mass of the solid put into the beaker. The sample must have been separated into its components.

You might be interested in
What results from a reaction of a base and a hydronium ion.
BartSMP [9]

Answer:

An acid

Explanation:

» The reaction of any hydrogen ion or hydroxonium ion with a base results into an acidic solution.

For hydrogen ions:

{ \rm{H {}^{ + }_{(aq)} +  Cl {}^{ - } _{(aq)} \:  \dashrightarrow \: HCl _{(aq)}  }}

For hydroxonium ions:

{ \rm{H _{3} O {}^{ + } _{(aq)}  +Cl {}^{ - }  _{(aq)} \:  \dashrightarrow \:HCl _{(aq)}   +  H _{2} O _{(l)}}}

6 0
3 years ago
Determine the electrical work required to produce one mole of hydrogen in the electrolysis of liquid water at 298°K and 1 atm. T
Ostrovityanka [42]

Explanation:

The given data is as follows.

          \Delta H = 286 kJ = 286 kJ \times \frac{1000 J}{1 kJ}

                            = 286000 J

 S_{H_{2}O} = 70 J/^{o}K,      S_{H_{2}} = 131 J/^{o}K

 S_{O_{2}} = 205 J/^{o}K

Hence, formula to calculate entropy change of the reaction is as follows.

          \Delta S_{rxn} = \sum \nu_{i}S_{i}_(products) - \sum \nu_{i}S_{i}_(reactants)

                     = [(\frac{1}{2} \times S_{O_{2}}) - (1 \times S_{H_{2}})] - [1 \times S_{H_{2}O}]

                    = [(\frac{1}{2} \times 205) + (1 \times 131)] - [(1 \times 70)]

                    = 163.5 J/K

Therefore, formula to calculate electric work energy required is as follows.

             \Delta G_{rxn} = \Delta H_{rxn} - T \Delta S_{rxn}

                            = 286000 J - (163.5 J/K \times 298 K)

                            = 237.277 kJ

Thus, we can conclude that the electrical work required for given situation is 237.277 kJ.

6 0
4 years ago
a compound has a percent compostion of carbon equal to 48.8383%, hydrogen equal to 8.1636%, and oxygen equal to 43.1981%. what i
Margarita [4]

Answer:

C₂H₃O

Explanation:

From the question given above, the following data were obtained:

Carbon (C) = 48.8383%

Hydrogen (H) = 8.1636%

Oxygen (O) = 43.1981%

Empirical formula =?

The empirical formula of the compound can be obtained as follow:

C = 48.8383%

H = 8.1636%

O = 43.1981%

Divide by their molar mass

C = 48.8383 / 12 = 4.07

H = 8.1636 / 1 = 8.1636

O = 43.1981 / 16 = 2.7

Divide by the smallest

C = 4.07 / 2.7 = 2

H = 8.1636 / 2.7 = 3

O = 2.7 /2.7 = 1

Thus, the empirical formula of the compound is C₂H₃O

8 0
3 years ago
What happens if the metal you throw in is MORE REACTIVE than the<br> metal ion in solution?
IRISSAK [1]
A displacement reaction Would occur in this situation
6 0
4 years ago
Which compound is held together by ionic bonds?<br><br> A. S02<br> B. H20<br> C. CaCl2<br> D. CH4
Elena-2011 [213]

Answer is: C. CaCl2.

Name of this chemical compounds is calcium chloride.

Calcium chloride is a inorganic salt with ionic bonds between calcium and chlorine.

It is a colorless crystalline solid at room temperature, highly soluble in water.

Calcium form cation with positive charge 2+ and chlorine form anion with negative charge 1-.

Electron configuration of calcium atom: ₂₀Ca 1s² 2s² 2p⁶ 3s² 3p⁶ 4s².  

Atomic number of calcium is 20, it means that it has 20 protons and 20 electrons, so atom of calcium is neutral.  

When calcium lost two electrons, it will have 20 protons (positive charge) and 18 electrons (negative charge), which means it has two protons more and it has +2 oxidation number.

6 0
3 years ago
Other questions:
  • It the mass of a material is 46 grams and the volume of the material is 8 cm ^3 What would the density of the material to be
    7·1 answer
  • How to calculate newtons?
    8·2 answers
  • Hot tea is best when served in china tea cups.<br><br> True<br> False
    10·1 answer
  • Which describes the force between two magnets winter south poles are almost touching
    11·2 answers
  • An aqueous solution contains 300 parts per million of KOH. Determine the number of grams of KOH present in 1000 grams of this so
    8·1 answer
  • PLEASE HELP!! WILL MARK BRAINLIEST
    14·1 answer
  • Which statements about thermal energy are true? Choose all answers that are correct. A. Temperature is a measure of the average
    8·1 answer
  • When atoms join together, the bond is either covalwnt or ionic
    11·1 answer
  • A solution mass of 1 kg is 10 times greater than 100 g, thus one kilogram (1 kg) of a 2.5% KI solution would contain of KI.
    12·1 answer
  • What is a diatom?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!