You divide by the mass of the solution.
Percent by mass is the mass of the solute divided by the mass of the solution, multiplied by 100.
Example:
You dissolve a 4.00 g sugar cube in 350 mL of tea at 80 °C. The density of water at 80 °C is 0.975 g/mL. What is the percent by mass of sugar in the solution?
Solution
Step 1 — Determine mass of the solute.
The solute is the sugar cube. Mass of solute = 4.00 g.
Step 2 — Determine mass of solvent.
The solvent is the 80 °C water. Use the density of the water to find the mass.
mass of solvent = 350 mL ×
0.975
g
1
mL
= 341 g
Step 3— Determine the total mass of the solution
mass of solution = mass of solute + mass of solvent = 4.00 g + 341 g = 345 g
Step 4 — Determine percent composition by mass of the sugar solution.
% by mass =
mass of solute
mass of solution
× 100 % =
4.00
g
345
g
× 100 % = 1.159 %
The percent composition by mass of the sugar solution is 1.159 %.
HELP 15-21 PLEASE ASAP!!
Answer:
15-21 is 6
Explanation:
At another temperature, the rate constant is 3.25 M-2 s-1. What is the rate at this temperature for the
given concentrations?
Answer:
It's 0.00015
Explanation:
got it right on edge 2021
How is enthalpy related to the spontaneity of a reaction?
A. AH=0 contributes to spontaneity.
B. AH<0 contributes to spontaneity.
C. AH> 0 contributes to spontaneity.
D. AH does not affect spontaneity.
Answer:
D
Explanation:
Gibb's free energy change(∆G) and Standard electrode potential of electrochemical (Ecell) determine the spontaneity of a reaction.
when ∆G > 0, the reaction is not spontaneous
∆G < 0, the reaction is spontaneous
∆G = 0, the reaction is in equilibrium
when Ecell > 0, the redox reaction is spontaneous
Ecell < 0, the redox reaction is not spontaneous
Ecell = 0, the redox reaction is in equilibrium.
ΔH < 0 contributes to spontaneity.
What is a spontaneous reaction?A spontaneous reaction is one that takes place naturally under a certain set of circumstances. The general entropy, or chaos, of the system increases in the presence of spontaneous reactions.How can we determine if a reaction is spontaneous or not?We can determine it by calculating Gibb's free energy.
How do we calculate Gibb's free energy?It is calculated by the formula:
ΔG = ΔH - TΔS
ΔG is the change in Gibb's free energy,ΔH is the change in the enthalpyΔS is the change in entropy.How does ΔG tells if a reaction is spontaneous or not?If ∆G > 0, the reaction is not a spontaneous reaction∆G < 0, the reaction is a spontaneous reaction∆G = 0, the reaction is in equilibriumHow does ΔH contribute to the spontaneity of the reaction?For a reaction to be a spontaneous reaction, ∆G < 0.Consider a reaction, ΔG will be calculated as ΔH - TΔSIf ∆H < 0 then the ΔH - TΔS will be a lesser value ( more negative) than it would have been when ∆H = 0 or ∆H > 0.Therefore ∆H < 0 contributes to spontaneity.To learn more about ΔH, spontaneous reaction, enthalpy, and entropy here,
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If there are 27 grams of nitrogen dioxide at STP how many liters does this occupy?
Answer:
30 liters
Explanation:
A force caused by objects moving in opposite directions called
Answer: Balanced forces
Explanation: Equal forces acting in opposite directions are called balanced forces. Balanced forces acting on an object will not change the object's motion.
Matthew was cleaning his car on a very hot summer day. He left the cleaning spray he had bought, and was using, on the driveway in the intense heat and the can exploded. Why did this happen?
Answer: The cleaning spray might have containing alcohol.
Explanation:
Some alcohol have the tendency to give an explosive effect on heating. According to the given situation, if the cleaning fluid is containing alcohol and when it had been exposed to air, oxygen and sun heat it will become unstable by producing peroxides which can explode the can in which they have been stored. So, in the given situation, the cleaning spray containing alcohol will explode due to intense heat.
is it unsaturated, saturated, or super saturated
Answer:
saturated
Explanation:
It is not dense enough to be supersaturated.
Answer:
unsaturated
Explanation:
salts arent fatty
What is the percent by volume of a solution that has 45 mL of ethanol CH3OH dissolved in 255 mL of water?
Answer:
Percent volume-volume (%(v/v)) = 100 x (volume of solute / volume of solution)
Percent volume-volume (%(v/v)) = 100 x (volume of solute / volume of solution)ex. 20 ml of methanol dissolved in enough water to make 200 ml of solution would result in a 10 % methanol solution
Percent volume-volume (%(v/v)) = 100 x (volume of solute / volume of solution)ex. 20 ml of methanol dissolved in enough water to make 200 ml of solution would result in a 10 % methanol solution-the units may be any units of volume you chose - as long as they are consistent
Percent volume-volume (%(v/v)) = 100 x (volume of solute / volume of solution)ex. 20 ml of methanol dissolved in enough water to make 200 ml of solution would result in a 10 % methanol solution-the units may be any units of volume you chose - as long as they are consistent-this concentration unit is most often used when mixing two liquids
Mass = 22g Volume = 2cm3 What is the Density?
Answer:
11g/cm^3
Explanation:
The density of a substance can be found By
density= Mass/volume
From the question
mass = 22 g
volume = 2 cm³
22/2=11
We have the final answer as
11 g/cm³
Answer:
11g/cm^3
Explanation:
It is because the constant formula density is
Density=Mass/ Volume.
Therefore we have
Density=22g/2cm^3
Which is = 11g/cm^3
Which indicator would show a pH change from 6 to 7?
A. Red litmus indicator
B. Methyl red indicator
C. Phenol red indicator
D. Blue litmus indicator
Answer:
c
Explanation:
1. litmus paper is used when showing a change between a greater range in ph levels - so A and D are automatically a no.
2. methyl red is used to show a range in ph levels between 4.8-6
3. Option C is the only one left so im going to assume its C because its definitely not A, B, or D
How can a weaker party impact the law making process?
Answer: This is due to a dominance of political parties over ... legislative process, the influence opposition has on amending the government bills and formal and effective
Explanation: hope u get it right
Explain Newton's 2nd Law of motion
Answer:
Newtons second law says that acceleration (gaining speed) happens when a force acts on a mass (object)
Explanation:
For example riding your bicycle, your bicycle is the mass and your leg muscles pushing on the pedals of your bicycle is the force.
The population size of panda
bears increases dramatically
The
population will decrease because
Answer:
it will decrease because there will not be food for all of them and there is very little space for them now so if there is more they will start to fight
Explanation:
there is very little habitat left for panda bears so if there population increases the food and space with be filed
Hello! jamilialves888
I'm glad you asked my name is ✰Tobie✰
And I will help you understand why the population of ⚝pandas ⚝
is decreasing .
-Your answer :βy Tobie
≛So why are pandas going extinct?
One of the main cause is due to the destruction of their own habitat
Since china is a country that is constantly growing their own homes are slowly being destroyed Since their habitats are becoming destroyed it forces them to live in small unhabitable area .
≛This leads to another problem.....
If they are forced to live in a small area there will be less food...
Since there is a shortage of food that will leave the panda's to slowly starve to death since pandas only eat bamboo they could never be able to live anywhere else....Another reason panda's are going extinct is because they are being hunted for their fur.
ex·tinct
/ikˈstiNG(k)t/
_____________
It means that the species does not exist anymore and
are no longer in existence
Hope this helps!
-Tobie <3
ʕ •ᴥ•ʔ
(0904) How many atoms are there in 56.2 grams of Krypton, Kr?
Answer:
56.2÷6.02×10^23
=9.34×10^23
Explanation:
Divide the given mass of the atom by the mass of an Atom (the avogadro's constant) to find the number of atoms in the given mass.
Define respiration in plants:
Define Transpiration in plants:
( Can’t be short has to at least be long or medium sized )
Answer:
Respiration in plants: The process of respiration in plants involves using the sugars produced during photosynthesis plus oxygen to produce energy for plant growth. In many ways, respiration is the opposite of photosynthesis. ... As with photosynthesis, plants get oxygen from the air through the stomata.
Transpiration in plants: The water eventually is released to the atmosphere as vapour via the plant's stomata — tiny, closeable, pore-like structures on the surfaces of leaves. Overall, this uptake of water at the roots, transport of water through plant tissues, and release of vapour by leaves is known as transpiration.
Sources (jic)
https://www.usgs.gov/special-topic/water-science-school/science/evapotranspiration-and-water-cycle
https://www.pthorticulture.com/en/training-center/basics-of-plant-respiration/
Good luck!!
When the medium is uniform, how do light waves travel through it?
a. vibrating motion
b. circular motion
c. irregular motion
d. straight line motion
Answer:
d.straight line motion
Answer:
d.) straight line motion
Explanation:
i just took the k12 test
What volume of 0.062 M HCl is needed to react to completely neutralize 19.4 mL of 0.050 M Ba(OH)2? *
Answer:
31.3 mL
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2HCl + Ba(OH)₂ —> BaCl₂ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, HCl (nₐ) = 2
The mole ratio of the base, Ba(OH)₂ (n₆) = 1
Finally, we shall determine the volume of the acid need for the reaction as follow:
Molarity of acid, HCl (Mₐ) = 0.062 M
Mole ratio of the acid, HCl (nₐ) = 2
Volume of base, Ba(OH)₂ (V₆) = 19.4 mL
Molarity of base, Ba(OH)₂ (M₆) = 0.050 M
Mole ratio of the base, Ba(OH)₂ (n₆) = 1
Volume of acid, HCl (Vₐ) =?
MₐVₐ / M₆V₆ = nₐ / n₆
0.062 × Vₐ / 0.050 × 19.4 = 2/1
0.062 × Vₐ / 0.97 = 2
Cross multiply
0.062 × Vₐ = 0.97 × 2
0.062 × Vₐ = 1.94
Divide both side by 0.062
Vₐ = 1.94 / 0.062
Vₐ = 31.3 mL
Thus, the volume of the acid needed is 31.3 mL
calculate the molecular mass of N2O3
the answer is 76.01g/mol
and the density:1.4g/cm³
TRUE OR FALSE?
It is not possible for wind can push an air parcel even higher in the troposphere, causing the parcel to cool and lose more energy, which will lead to more rainfall.
Answer:
The more water vapor in the air parcel, the more condensation can occur, and therefore, more rain. ... The air parcel then loses more energy, causing more rainfall. Wind pushes air parcels even higher in the troposphere, where it is colder. The air parcels will then lose more energy and more rain can happen.
I think is FALSE, is that right?
When CuCl2 reacts with NaNO3, copper (II) nitrate and sodium chloride are formed.
a) Write the balanced equation for the reaction given above:
CuCl2 + NaNO3 à Cu(NO3)2 + NaCl
Answer:
CuCl2 + 2NaNO3 -------> Cu(NO3)2 + 2NaCl
hope this helps
good day mate
Given the balanced chemical equation: 2 H2 + O2 → 2 H20. Choose
the description below that most accurately describes the reaction.
O 2 moles of hydrogen react with 1 mole of oxygen to form 2 moles of water
O 2 moles of water react with 1 mole of hydrogen to form 2 moles of oxygen
O equal moles of hydrogen and oxygen react to form an equal amount of
water
O 4 moles of hydrogen react with 2 moles of oxygen to form 4 moles of water
Answer:
The answer is
2 moles of hydrogen react with 1 mole of oxygen to form 2 moles of water
SCIENCE ANSWER ASAP PLEASE!!
A piece of metal of mass 23 g at 100 ◦C is
placed in a calorimeter containing 55.4 g of
water at 25◦C. The final temperature of the
mixture is 63.4
◦C. What is the specific heat
capacity of the metal? Assume that there is
no energy lost to the surroundings.
Answer in units of J
g ·
◦ C
.
Answer:
10.58 J/g-°C
Explanation:
To find the specific heat capacity of the metal, you need to know how much heat was lost when it reacted with water.
You know that there are 55.4 g of water, the initial temp. of water is 25°C, and the final temp. (the mixture's temp.) is 63.4°C.
You should also know that the specific heat capacity of water is 4.186 J/g-°C.
Plug this into the equation the q=mcΔT.
q = (55.4 g)(4.186 J/g-°C)(63.4°C - 25°C)
q = 8905.12896 J
If 8905.12896 J was gained by the water, then 8905.12896 J must have been lost from the metal.
You know that there are 23 g of the metal and that its initial temp. is 100°C.
Plug this information into q=mcΔT.
8905.12896 J = (23 g)(C)(63.4°C - 100°C)
C = 10.58 J/g-°C
*When you plug all of this into the calculator, it will result in a negative number but keep in mind that heat was LOST by the metal so 8905.12896 J is essentially negative. So the negative cancels out.*
. What is the total voltage of the circuit, if you install two D-cell batteries in a flashlight so that their positive ends are facing each other compared to If you installed the batteries with the positive and negative terminal facing each other
Answer:
0
Explanation:
A voltage makes the electric charges to move.
When we install a D - cell batteries in the flashlight with their positive ends facing each other, as compared to the batteries installed with their positive and negative terminals facing each other, the flashlight will not work as the total voltage across the two batteries will be zero.
Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
The given question is incomplete. The complete question is:
Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na+(aq) + Cl −(aq) Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
Answer: The entropy change is positive. The free energy change for the process is negative and reaction is spontaneous.
Explanation:
Entropy is defined as the degree of randomness of a system. For a system in which randomness increses , the enetropy is said to increase and [tex]\Delta S[/tex] is positive.
As in the given reaction : [tex]NaCl(s)\rightarrow Na^+(aq)+Cl^-(aq)[/tex] , the solid is dissociating to give ions , randomness increases and thus entropy is positive.
Also the dissociation of a molecule requires energy , thus the enthalpy [tex]\Delta H[/tex] is also positive as heat is absorbed by the system.
[tex]\Delta G=\Delta H-T\Delta S[/tex]
[tex]\Delta G=(+ve)-T(+ve)[/tex]
[tex]\Delta G=-ve[/tex] when Temperature is high.
Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na+(aq) + Cl −(aq)
Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
The given question is incomplete. The complete question is:
Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na(aq) Cl −(aq) Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
Answer: The entropy change is positive. The free energy change for the process is negative and reaction is spontaneous.
Explanation:
Entropy is defined as the degree of randomness of a system. For a system in which randomness increses , the enetropy is said to increase and is positive.
As in the given reaction : , the solid is dissociating to give ions , randomness increases and thus entropy is positive.
Also the dissociation of a molecule requires energy , thus the enthalpy is also positive as heat is absorbed by the system.
when Temperature is high.
Which of these ideas did you include in your answer?
✔️ When a crystalline solid dissolves, it becomes more disordered.✔️ When disorder increases, ΔG is positive.✔️ This process probably has a positive ΔS .✔️ The process is spontaneous.✔️ Spontaneous processes have ΔG < 0; the process has a negative ΔG .
Have a Nice Day .
What would be the effect on this reaction of increasing the temperature?
2H2 + O2 = 2H20 + energy
A) the rate of formation of H2O would increase
B) The forward reaction would be favored
C) Increasing the temperature would not have an effect on this reaction
D) The rate of the forward reaction would decrease
Answer:
D) The rate of the forward reaction would decrease
Explanation:
The statement that describes effect on the reaction of increasing the temperature is "the rate of the forward reaction would decrease."
What is temperature?Temperature is the measurement of a body's level of hotness or coolness.
The average kinetic energy of the system is measured by temperature. The kinetic energy of particles in a matter raises as they move faster, which boosts the temperature of the system. When two bodies of differing temperatures come into touch, heat is the energy exchanged between them.
The term "exothermic reaction" refers to a reaction that releases energy. An exothermic reaction, in other words, produces heat. The temperature of the reaction will rise unless it is cooled in some way. When you use an external heater to raise the temperature, it slows or reverses the reaction, reducing the number of products while increasing the amount of reactants.
Hence the correct answer is D.
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For the following equation insert the correct coefficients that would balance the equation. If no coefficient is need please insert the NUMBER 1.
1. CH4 + O2 --> CO2 + H2O
Answer:
1CH₄ + 2O₂ -> 1CO₂ + 2H₂O
Explanation:
Reactants:
1 C
4 H
4 O
Products:
1 C
4 H
4 O
The equation is balanced.
The heat capacity of aluminum is 0.900 J/gºC. a. How much energy is needed to raise the temperature of an 8.50 x 102g block of aluminum from 22.8°C to 94.6°C?
Recall the heat capacity equation:
q = mc∆T
We're given mass, specific heat capacity, as well as the change in temperature. All we need to do is plug the numbers into the variables and we'll have our answer!
Although this question doesn't try to trick you, more often than not questions regarding energy change will attempt to throw you off with specific heat capacity. It's extremely important to note the units of the specific heat capacity and ensure that the numbers you use are in those units. As an example, the specific heat capacity might be given to you in J/mol*K - in this case, you'd have to do some unit conversions with your given data in order to fit all the numbers. In this question, we're given the specific heat capacity in J/gºC, so we don't need to change anything since all of our data is already in these units.
Anyways, back to the actual question:
q = mc∆T
q = (8.50 * [tex]10^{2}[/tex]) * (0.900) * (94.6 - 22.8)
q = 54927 (J)
Remeber to include significant figures:
54927 = 5.49 * 10^4 (J)
The required energy is 5.49 * [tex]10^{4}[/tex] Joules, or 5.49 * [tex]10^{1}[/tex] kJ
Let me know if you need any of my work to be explained!
- Breezeツ
Sometimes the number of electrons in an atom changes. These atoms are called what
Answer:
ions
Explanation:
convert 2.41 x 10^2 m to cm
answer choices
2.41cm
2.41 x 10^4cm
2.41 x 10^-2cm
2.41 x 10^-6cm
Answer:
2.41*10² m equals 2.41*10⁴ cm
Explanation:
The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other) , the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:
a ⇒ b
c ⇒ x
So: [tex]x=\frac{c*b}{a}[/tex]
In this case the rule of three can be applied as follows: if 1 m equals 100 cm, 2.41*10² m equals how many cm?
[tex]cm=\frac{2.41*10^{2} m*100 cm}{1 m}[/tex]
cm= 24100 = 2.41*10⁴
2.41*10² m equals 2.41*10⁴ cm