Percent yield = 70%
Further eplanationPercent yield is the comparison of the amount of product obtained from a reaction with the amount you calculated
General formula:
Percent yield = (Actual yield / theoretical yield )x 100%
An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients
Reaction
2H₂ (g) + O₂ (g) → 2H₂O (g)
mass of H₂O (theoretical) :[tex]\tt mass=mol\times MW(mol~ratio~H_2O\div H_2=2\div 2)\\\\mass=(\dfrac{2}{2}\times \dfrac{13.8}{2})\times 18~g/mol\\\\mass=124.2~g[/tex]
percent yield[tex]\tt \%yield=\dfrac{87}{124.2}\times 100\%=\boxed{\bold{70\%}}[/tex]
The element with the smallest iconic radius in the alkaline earth metals is
Answer:
Metal.
Explanation:
Metal has the smallest iconic radius in the alkaline earth metal.
8. The following system contains 20.0 psi each of gases A and B in the end bulbs with an evacuated bulb in the centre. Both stopcocks are opened at once. What is the new overall pressure in the system?
I literally have no idea how to even start this, I know that the answer is 13.3 psi, but I don't have any clue why or how to get there.
Answer:
13.3
Explanation:
Before opening the stopcocks you have 40psi in total.
After that, those 40psi will be divided into 3bulbs, so 40/3=13.3psi for the system.
A student investigated the time taken for amylase to breakdown a 10% starch solution into glucose at
37°C. The student repeated the investigation five times
Figure 11 shows the results
time taken for amylase to produce glucose (s)
Test 4
120
125
110
115
Figure 11
() Calculate the rate of amylase enzyme activity for the 10% starch solution.
Answer:
Phenolphthalein is an indicator. It is pink in alkaline solutions and turns colourless as the pH decreases.
It can be used to measure the activity of the enzyme lipase on the breakdown of lipids.
Samples of milk containing phenolphthalein were incubated with lipase at different temperatures.
The time taken for the phenolphthalein to turn colourless was recorded and used to calculate the rate of enzyme activity.
Figure 10 shows these results.
Picture
(a) (i) Explain why phenolphthalein turns colourless when lipase breaks down the lipids in milk. (2)
(ii) Describe the effect of temperature on the activity of lipase, as shown in Figure 10. (2)
(iii) Explain why the activity of lipase changes above a temperature of 40°C. (2)
(b) A student investigated the time taken for amylase to breakdown a 10% starch solution into glucose at 37°C. The student repeated the investigation five times.
The diagram is a model of one way that materials move into a cell.
Which Sentence explains what happens in last step?
A. a vacuole carries particles into the cell
B. The cell membrane surrounds particles outside the cell.
C. Phospholipids in the cell membrane allow particles to pass through
D. Transport proteins push particles out of cell.
Answer:
B. The cell membrane surrounds particles outside the cell.
Explanation:
The last step is when the cell membrane completely surrounds particles outside the cell.
This process is often known as endocytosis.
endocytosis is the process whereby a cell ingests materials by engulfing them using the cell membrane. In this process, the cell membrane completely covers the food.Fluorine (F) and bromine (Br) are in the same group on the periodic table. How do atoms of these elements compare when they form bonds?
Both a fluorine atom and a bromine atom lose one electron, and both atoms become stable.
A fluorine atom becomes stable by losing one electron, but a bromine atom cannot become stable by losing only one electron.
Both a fluorine atom and a bromine atom gain one electron, and both atoms become stable.
A fluorine atom becomes stable by gaining one electron, but a bromine atom cannot become stable by gaining only one electron.
Answer:
Both a fluorine atom and a bromine atom gain one electron, and both atoms become stable.
Explanation:
The two elements compare when they form bonds in that when both a fluorine atom and a bromine atom gain one electron, they both become stable.
Fluorine and bromine are elements called halogens. They both belong to group 7 on the periodic table. When they gain an electron each, they become isoelectronic with a corresponding noble gas. This gives their atom special stability.Answer:
3) Both a fluorine atom and a bromine atom gain one electron, and both atoms become stable
Explanation:i got it right on the quiz
hope this helps
what are cons of viruses ?????? oh dont mind this i jus gotta get this out of my head dont stop pop tht pop tht mhm jus like tht mhm shake it shake it mhm work it work it!!!!!!!!!!!
Answer:
Viruses can weaken your immune system. They make you sick. Some could even cause death.
Explanation:
I hope this helped I heard that song I forgot the name lol
Determine a skier's velocity in km/h, if it takes her 1.7 min to ski down a
1.67 km slope.
Answer:
103
Explanation:
do not listen to the haters
What is the term that refers to the rate of change in an object’s velocity?
Group of answer choices
momentum
acceleration
force
speed
Answer: Acceleration
Explanation:
Acceleration. The rate of change of an objects velocity is essentially the derivative of the velocity which is acceleration
(?)Li2O + (?)H2O → (?)LiOH
what goes inside the question marks?
Answer:
(1)Li2O + (1)H2O → (2)LiOH
Hope this helps!
8. Which type of element requires the least amount of energy to remove an electron?
Answer:
nonmetals
Explanation:
Which of the following materials would probably be used as a conductor of electric current in a computer chip?
A rubber
B. glass
c. plastic
D. gold
Answer:
gold is metal which is a very good conductor for electric current and most chips are made out of it.
Answer:
The answer is D. gold
Explanation:
¿Por qué un trozo de sal común es frágil y se puede romper fácilmente cuando se le somete a una fuerza y no ocurre lo mismo con un trozo de metal que se deforma antes de romperse?
Answer:
Explanation:
La sal común es un compuesto iónico, es decir que sus átomos (Na y Cl) están unidos entre sí por fuerzas electrostáticas, y el metal está unido entre sí por uniones metálicas. La naturaleza de estas uniones es diferente y en base a las fuerzas de atracción que hay entre los átomos en compuestos con este tipo de uniones, la propiedades físicas generales serán diferentes.
En el caso de los metales, los átomos metálicos están colocados unos sobre otros de forma ordenada, pero no fijamente retenida, y los electrones de valencia están delocalizados a través de todo el cristal metálico. Por esta razón, cuando se le aplica una fuerza a un metal, estos átomos pueden deslizarse unos sobre otros. Ésta es la propiedad que le da a los metales su maleabilidad.
En el caso de los compuestos iónicos, los aniones y cationes que lo componen están ordenados en el cristal de una forma más rígida y por eso cuando se les aplica una fuerza éstos compuestos se rompen mucho más fácil, ya que no pueden deformarse.
What does “like dissolves like” mean?
a
solvents dissolve chemicals with the same color (ex. both are green)
b
solvents dissolve chemicals made by the same company (ex. both made by Dow)
c
solvents dissolve chemicals with the same polarity ( ex. both are polar)
d
solvents dissolve chemicals with the same size (ex. both are 3 inches)
Answer:
c solvents dissolve chemicals with the same polarity ( ex. both are polar)
Explanation:
Like dissolves like is one of the central rule that guides the solubility of one substance in another.
It fully suggests substance having the same nature as in polarity-wise will dissolve one another. For example, water is a polar liquid, it will dissolve table salt because it i also polar. Water cannot dissolve oil because oil is non-polar.Which of the following are soluble in water: salt, gravel, or pepper
Atoms and ions are all the same.
Answer:
Yes they are
Explanation:
What human activity has caused the Increase of CO2 in the atmosphere?
What causes high and low tides?
O A. Variations in salinity and temperature transmit waves across the
ocean.
B. As Earth rotates, the moon's gravity pulls on different parts of the
planet.
C. Ocean water is driven by differences in water density.
D. Underwater disturbances displace large amounts of water.
SUBMIT
Which best describes the current model of the atom?
O A a central nucleus containing protons with electrons orbiting in specific paths
O B. a solid sphere unique for everything that exists
O c a solid sphere with electrons and protons embedded
O D. a central nucleus containing protons and neutrons with electrons orbiting in levels of high probability
Explanation:
i think the answer might be D
The number of atoms of an element in a chemical formula is given by the _________.
Answer:
Explanation: In a chemical formula, the symbols for each element in the compound are followed by subscripts that tell us how many of that element are in the compound. The subscripts that follow each element's symbol indicate how many of that element are in the compound. Notice how H is located in more than one place.
Explanation:
If a disease destroying barley plants in a field swept through an ecosystem, what would happen to the barley eating bird populaiton in the field?
Answer:
It would decrease
Explanation:
In an ecosystem, organisms feed on one another for survival due to the fact that energy needed for metabolic activities in individual organisms can only be obtained via food. This question depicts that certain bird population feeds on barley plant in an ecosystem.
However, If a disease attacks the plants in such a way that it destroys the barley plants in the field, this would cause the barley-eating bird population to DECREASE because their food source has been affected.
Answer:
the barley-eating bird population in the field would decrease.
Explanation:
A 7.0 liter balloon at room temperature contains helium gas. if the temperature is halved, what happen to the volume?
The volume = 6.71 L
Further explanationCharles's Law
When the gas pressure is kept constant, the gas volume is proportional to the temperature
[tex]\tt \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}[/tex]
V₁=7 L
T₁=25 °C(room temperature) + 273 = 298 K
T₂=12.5(halved) + 273 = 285.5 K
[tex]\tt \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}\\\\\dfrac{7}{298}=\dfrac{V_2}{285.5}\\\\V_2=6.71~L[/tex]
A gas occupies a volume of 0.444 L at 0.00C and
79.00 kPa. What is the final Kelvin temperature when
the volume of the gas is changed to 1880. mL and the
pressure is changed to 38.70 kPa?
Include unit of measurement and use proper
significant figures.
Answer:
The final temperature is 566°K
Explanation:
Given
V1 = 0.444L
T1 = 0.00°C
P1 = 79.00 kPa
V2 = 1880mL
P2 = 38.70 kPa
Required
Determine the final temperature of the gas
To answer this, we make use of idea gas law equation.
This is:
(P1V1)/T1 = (P2V2)/T2
Convert V1 to mL
V1 = 0.444L
V1 = 0.444 * 1000mL
V1 = 444mL
Convert T1 to Kelvin
T1 = 0.00°C
T1 = 0.00 + 273K
T1 = 273K
Substitute these values in the given equation.
(P1V1)/T1 = (P2V2)/T2
(79 * 444)/273 = (38.70 * 1880)/T2
35076/273 = 72756/T2
Cross Multiply
35076 * T2 = 273 * 72756
35076T2 = 19862388
Make T2 the subject
T2 = 19862388 ÷ 35076
T2 = 566K (approximated)
Hence, the final temperature is 566°K
You have 16.6 g of water at 40.2 C. How many Joules are needed to warm the water to 44.8 C?
Answer:
Q = 319.49 J
Explanation:
Given that,
Mass, m = 16.6 g
Initial temperature, [tex]T_i=40.2^{\circ} C[/tex]
We need to find the heat needed to warm the water to 44.8 °C. The formula that is used to find the heat required is given by :
[tex]Q=mc\Delta T\\\\Q=mc(T_f-T_i)\\\\Q=16.6\ g\times 4.184\ J/g^{\circ} C\times (44.8-40.2)^{\circ} C\\\\Q=319.49\ J[/tex]
So, 319.49 J of heat is needed to warm water.
pt Which of the following is an example of potential energy?
A. a rolling ball
B. a turning windmill
C. a compressed spring
D. a moving train
Answer:
C . a compressed spring
a copper ore contains 3.00% of copper carbonate, CuCO3, by mass. Which mass of copper would be obtained from 1 tonne of the ore?
A 1.91kg B 3.71kg C 15.3kg D 58.4kg
Answer:
(c) 15.39 kg of copper present in 1tonne of ore.
Explanation:
We are given that ore contains 3% of copper carbonate
1tonne = 1000kg
3% of copper carbonate in 1000kg of ore will be
= [tex]\frac{3}{100}*1000[/tex] = 30kg
30 kg of copper carbonate is present in ore
CuCO3 has 63.5g of cupper present in it
molar mass of CuCO3 = 123.5
so the percentage of copper present in CuCO3
= [tex]\frac{63.5}{123.5}*100[/tex] = 51.3% of copper present per kg CuCO3
Now
amount of copper present in 30kg of CuCO3
= [tex]\frac{51.3}{100}* 30[/tex] = 15.39kg
15.39 kg of copper present in 1tonne of ore
The mass of copper obtained from 1 tonne of the ore is 15.4 kg
The copper ore has 3% of copper carbonate by mass.
The mass of copper carbonate in 1 tonne of the ore can be calculated below.
1000 kg = 1 tonne
Therefore,
mass of copper carbonate = 3 /100 × 1000 = 30 kg
atomic mass of copper = 63.5 g
molar mass of CuCO₃ = 123.55 g
123.55 g of CuCO₃ gives 63.5 g of copper
30, 000g of CuCO₃ will give ? of copper
cross multiply
mass of copper = 30,000 × 63.5 / 123.55
mass of copper = 1905000 / 123.55 = 15418.8587616 g
mass of copper = 15418.8587616 / 1000 ≈ 15. 4 kg
read more: https://brainly.com/question/1237330?referrer=searchResults
What are the advantages of using resources such as geothermal energy, solar energy, and hydropower?
They produce large amounts of energy from burning fuels.
They can generate power by burning wastes.
They come from energy sources that never run out.
They increase the amount of greenhouse gasses.
The _____________ is similar to a vacumn cleaner because it cleans up cell waste.
a
endoplasmic reticulum
b
lysosome
c
mitochondria
d
cell wall
1 point
What would 140000000.0 be in scientific notation?
a. 1.4 x10-8
b. 1.4 x108
c. 14 x10-7
d. 14 x107
Answer:
B
Explanation:
you're moving the decimal 8 spots to the left so it can only be B
HELP ASAP
Describe the function of Cytokinesis in the cell cycle.
Find the density of a 720.0 g block of Titanium with these dimensions: L = 10.0 cm, W = 8.0 cm, H = 2.0 cm