A student is given a sample of matter and asked to determine whether it is an element, compound, or mixture. The student discovers that she cannot separate
the components of the sample by physical means. However, she is able to separate the sample by chemical means into three different pure substances. The
sample must be______.
A. an element
B. a compound
C. a mixture
D. a solution
Answer is B
A mixture means two compounds mixed together but not atomically. For example, sand and water solution. A water with sand mixed inside is a mixture because the sand can be separated by physical means.
Water is H2O. This means it is a compound, because hydrogen and oxygen is bonded together atomically. Hydrogen however is an element, because you can't seperate it anymore (You could seperate it in the sense of protons and neutrons, but the definition of element is something you can see on the periodic table)
Compound means more than one element bonded together.
The sample must be a compound because it couldn't be seperated by physical means but can be seperated by chemical means into three pure substances (synonym of element)
2NH3+2O2- N2O+3H2O
If 80.0 grams of O2 reacted in above reaction ,how many grams of N2O will be produced?
Answer:
55.0125 grams NO2
Explanation:
So we have 80 grams of O2, first convert to moles
80 g O2 * 1 mol/32 g O2 = 2.5 mol O2
Next use the mole ratio of O2 to NO2
2.5 mol O2* 1 mol NO2/2 mol NO2=1.25 mol NO2
Since the question is asking how many grams, convert NO2 to grams
1.25 mol NO2 * 44.01 NO2/1 mol NO2= 55.0125 grams
A relationship in which one variable increases as the other variable decreases is an inverse relationship.
CA. True
B. False
Answer:
TRUE
Explanation:
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If the density of a sample of skim milk is 1.04 g/mL, how many grams are in 0.50 qt of skim milk?
Answer:
16grs in 0.5ml of milk
Explanation:
16gr in 0.5 ml of milk
how much energy must be released by 50.0 g of steam to decrease its temperature from 125.0 degrees Celsius to 100.0 degrees Celsius ?
Answer:
5250 Joules
Explanation:
Mass = 50g
Initial Temperature = 125.0 degrees Celsius
Final Temperature = 100 degrees Celsius
Temperature change = Final - Initial = 100 - 125 = -25
Heat = ?
These quantities are related by the equation;
H = mCΔT
where c = specific hear capacity = 4.2 J/g°C
H = 50 * 4.2 * (-25)
H = -5250 J (The negative sign is because heat is being released)
chemical formula for calculating pressure
Answer:
First, let's review the ideal gas law, PV = nRT. In this equation, 'P' is the pressure in atmospheres, 'V' is the volumes in liters, 'N' is the number of particles in moles, 'T' is the temperature in Kelvin and 'R' is the ideal gas constant (0.0821 liter atmosphere per moles Kelvin).
Explanation:
I majored in Chemistry
can you help me with my science
How many formula units make up 21.6 g of magnesium chloride (MgCl2)? Express the number of formula units numerically.
1.37 × 10²³ formula units MgCl₂
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 21.6 g MgCl₂
Step 2: Identify Conversions
Avogadro's Number
[PT] Molar Mass of Mg - 24.31 g/mol
[PT] Molar Mass of Cl - 35.45 g/mol
Molar Mass of MgCl₂ - 24.31 + 2(35.45) = 95.21 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 21.6 \ g \ MgCl_2(\frac{1 \ mol \ MgCl_2}{95.21 \ g \ MgCl_2})(\frac{6.022 \cdot 10^{23} \ formula \ units \ MgCl_2}{1 \ mol \ MgCl_2})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 1.36619 \cdot 10^{23} \ formula \ units \ MgCl_2[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.36619 × 10²³ formula units MgCl₂ ≈ 1.37 × 10²³ formula units MgCl₂
You have two compounds that you have spotted on a TLC plate. One compound is more polar than the other. You run the TLC plate with neat hexanes and find that only one spot moved a small distance up the plate. Next you made a 50/50 mixture of hexanes and ethyl acetate. What might you expect to see on your TLC plate (what would the spots do)?
Answer:
The two spots will move up the plate.
Explanation:
We have to first understand the rudiments of chromatography. In chromatography, there is a stationary phase and a mobile phase. The stationary phase does not move. In this case, the stationary phase is the TLC plate.
The mobile phase is the solvent used to perform the chromatography. The movement of the spots depends on the composition of the solvent.
When neat hexane was used, only one spot was moved. This must be due to the interaction of the nonpolar hexane with the less polar compound. However, when a 50/50 mixture of hexanes and ethyl acetate is used, the both compounds are found to move up the plate.
Can someone help me please
Answer:
the answers are a, f, g
and lastly e because they all describe a liquid
What types of energy do lamps give off?
Include how was your day in you answer.
Explain why/if the lamp gives off heat energy.
Answer:
When a lamp is turned on, it gives off light energy and heat energy.
My day was fantastic.
Explanation:
The lamp gives off heat energy because anything that gives off light energy gives off heat energy.
Is nitric acid a strong or weak acid. Explain your answer.
Answer:
There are only a few (7) strong acids, so many people choose to memorize them. All the other acids are weak. The strong acids are hydrochloric acid, nitric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, perchloric acid, and chloric acid.Explanation:
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A balloon of hydrogen is subjected to vacuum. The initial pressure and volume of hydrogen is 0.95 atm and 0.55 L. Calculate the final pressure if the final volume is 1.22 L?
Answer:
0.43 atm
Explanation:
From the question given above, the following data were obtained:
Initial pressure (P₁) = 0.95 atm
Initial volume (V₁) = 0.55 L
Final volume (V₂) = 1.22 L
Final pressure (P₂) =?
The final pressure of the gas can be obtained by using the Boyle's law equation as follow:
P₁V₁ = P₂V₂
0.95 × 0.55 = P₂ × 1.22
0.5225 = P₂ × 1.22
Divide both side by 1.22
P₂ = 0.5225 / 1.22
P₂ = 0.43 atm
Therefore, the final pressure of the gas is 0.43 atm
The final pressure of the gas is 0.43 atm.
What is pressure?Pressure is the process of force exerted perpendicular to any surface.
Given, the Initial pressure (P₁) is 0.95 atm
The initial volume (V₁) is 0.55 L
The final volume (V₂) is 1.22 L
To find the final pressure (P₂)
By the Boyle's Law
[tex]\rm P_1V_2= P_2V_2[/tex]
[tex]\rm 0.95\times 0.55 = P_2\times1.22\\\\0.5225 = P_2 \times 1.22\\\\Divided\;both \;side\;by\;1.22\\\\P_2=\dfrac{0.5225}{1.22} = 0.43 atm.[/tex]
Thus, the final pressure of the gas is 0.43 atm.
Learn more about pressure, here:
https://brainly.com/question/356585
Which of the following is true?
A)If we know that a reaction is an elementary reaction, then we know its rate law.
B)The rate-determining step of a reaction is the rate of the fastest elementary step of its mechanism.
C)Since intermediate compounds can be formed, the chemical equations for the elementary reactions in a multistep mechanism do not always have to add to give the chemical equation of the overall process.
D)In a reaction mechanism, an intermediate is identical to an activated complex.
E)all of these statements are true.
Answer:
If we know that a reaction is an elementary reaction, then we know its rate law.
Explanation:
An elementary reaction is a reaction that takes place in one reactive encounter. This means that the two species interact in a single step to give the products.
If two reactants interact in a single step to yield the products then we can easily deduce the rate law from the reaction equation.
For instance, For the reaction;
2A + B → C
The rate law is
rate = k[A]²[B].
If the reaction is an elementary reaction and the equation of the reaction is balanced, then we can deduce the rate law from the balanced reaction equation.
formula for calculating pressure
Answer:
The formula for pressure is P = F/A, in which P is pressure, F is force, and A is area.
Explanation:
Burning plants contributes to global warming because:
a) carbon dioxide is released during combustion
b) there are no trees to provide shade
c) much oxygen is used up during combustion
d) the sun beats on the bare soil.
Answer:carbon dioxide is released during combustion
How much of NaCl is in 1.14 L of 0.400 M
NaCl?
Answer:
44 g NaCI
Explanation:
The problem provides you with the molarity and volume of the target solution, so your first step here will be to use this information to figure out how many moles of sodium chloride.
if an atom has 22 protons 28 neutrons 20 electrons what would its atomic number be
Answer:
22
Explanation:
The atomic number indicates the amount of protons, so it would be 22
To date, scientific tests of astrology have never found that its predictive methods work.
True
False
true______________________
The pressure 15.0 m under water is 248 kPa.
What is this pressure in torr
Answer:
1860 torr
Explanation:
In order to convert from kPa to torr, we are going to use the following conversion factor:
1 kPa = 7.5 torrNow we multiply 248 kPa with this factor so that the kPa units cancel each other and only the torr units remain:
248 kPa * [tex]\frac{7.5torr}{1kPa}[/tex] = 1860 torrThis means that the answer is 1860 torr.
As human populations grow, it becomes more important to use renewable sources of energy. Which of the following objects uses energy from a renewable source?
A-a stove that is powered by natural gas
B- a refrigerator that runs on solar power
C- a lantern that burns oil from beneath Earth's surface
D- a toaster that uses electricity from a coal-burning power plant
Which processes are part of the fast carbon cycle?
A) Transpiration and fossil fuel formation
B) Transportation and photosynthesis
C) Cellular respiration and photosynthesis
D) Deforestation and fossil fuel formation
Answer:
B) Transportation and photosynthesis
C) Cellular respiration and photosynthesis
I HAVE 25 MINUTES TO FINISH True or false the deeper you go into Earth the temperature goes up ?
Answer:
true
Explanation:
you are getting closer to the core hope this helps!
How many grams of sodium (Na) are in 6.2 mol of Na?
mass = mol no. x molar mass
= 6.2 x 23
= 142.6 g
Liquid hydrogen boils at -252°C. What is the boiling point on the Kelvin scale?
Answer:
Boiling point in kelvin is 373.1 \
boiling point of liquid hydrogen in kelvin is 21.15
Explanation:
I need help ASAP pls
Answer:
A should be the swer n
Explanation:
A closed, nonreactive system contains species Aand Bin vapor/liquid equilibrium. Species Ais a very light gas, essentially insoluble in the liquid phase. The vapor phase contains both species Aand B. Some additional moles of species Bare added to the system, which is then restored to its initial T and P. As a result of the process, does the total number of moles of liquidincrease, decrease, or remain unchanged?
Answer:
Remain unchanged.
Explanation:
The total number of moles of liquid remain unchanged as the some moles of species B are added to the system because specie B that is added in the liquid phase is again restored after addition. If the specie B did not restored after addition to the liquid phase so the total number of moles increases in the liquid phase so that's why we can say that the liquid phase remain unchanged.
A flexible container is filled with He(g) to a volume of V1 at a temperature of 150K. The container is then heated at constant pressure to a temperature of 300K. What is the final volume of the container?
a. V1/3b. V1/2c. V1d. 2V1
Answer:
a but it might also be c
Explanation:
i d k what this is
Answer:
2V1
Explanation:
Which of the following is not a valid conversion factor?
Answer:
d
Explanation:
Can metals take away electrons from non metals?
Answer:
Well no because if metals lose electrons, any non-metal sources/items gain electrons from the metal.
Answer:
Metals tend to lose electrons and non-metals tend to gain electrons, so in reactions involving these two groups, there is electron transfer from the metal to the non-metal
Explanation: