1. Lauri conducts an experiment to investigate how the mass of a catalyst, manganese (IV) oxide, affects the rate of production of oxygen during the decomposition of hydrogen peroxide (H2O2). Water and heat are also produced during the decomposition.
(a) (i) Name TWO factors OTHER THAN a catalyst, which can affect the rate of a chemical reaction. (2mks)
(ii) Write a balanced equation to show the decomposition of hydrogen peroxide by manganese (IV) oxide, MnO2(s) (2mks)
Answers
a)(I)the concentration of the reactants
the temperature
ii)
Related Questions
You have 16.6 g of water at 40.2 C. How many Joules are needed to warm the water to 44.8 C?
Answers
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.
the atomic number tells us all of the following except ..
Answers
Answer:
b
Explanation:
The atomic number tells us all of the following except B. The order in which the elements were discovered.
What does the atomic number let you know?
The atomic number is the number of protons in the nucleus of an atom. The number of protons outline the identity of detail (i.e., an element with 6 protons is a carbon atom, no matter how many neutrons may be present).
What pieces of facts do the atomic number inform you?The atomic variety helps human beings discover factors in step with the variety of protons one atom of the element has. It essentially defines the element. while having a neutral rate, it also offers the variety of electrons the detail has (in one atom). while isotopes are a component, it would not completely exchange the atom.
Learn more about Atom at https://brainly.com/question/6258301
#SPJ2
Boron- 11
Atomic #
Atomic mass
# of protons
# of neutrons
# of electrons
Answers
Answer: 5 protons 6 neutrons and 5 electrons. and atomic number is 5.
Hope this helps!
Please help me with my Chemistry homework!! I have so much homework to do for other classes and I’m so stressed so even answering one question would be amazing!!!
1. A graduated cylinder had an initial volume of water of 22 mL. After an iron nail is dropped into the cylinder, the water rises to 38 mL. What is the volume of the nail?
2. Ms.Chavez dropped a gold ring into a graduated cylinder filled with water. The water level was originally at 20 mL. Now the water is at 25mL. Ms.Chavez knows that means the volume of the ring is 5 mL. What else would she have to do to find the density of her ring? Explain.
3. A simple of liquid propanol has a volume of 20.0 cm*^3 and a mass of 15.0 g. What is the density of propanol? Write only your answer below.
Answers
2. She need to find the mass, as density is mass divided by volume.
3. 0.75 g/cm^3
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
Answers
Answer:
C . a compressed spring
Rain freezes as it hits the ground to form solid water is this a physical change or chemical change?
a. Physical change
b. Chemical change
Can someone help me answer this I will give your brainliest
Answers
Answer:
It is Physical Change
Explanation:
Because it is just water turning into another substance of water, nothing chemical is happening.
How do you calculate wavelength and frequency?
Answers
Answer:
Wavelength can be calculated using the following formula: wavelength = wave velocity/frequency. Wavelength usually is expressed in units of meters. The symbol for wavelength is the Greek lambda λ, so λ = v/f.
Explanation:
Just a formula that's commonly used in biology.
How is a "decay event' recorded
Answers
Hope that helps.
Determine a skier's velocity in km/h, if it takes her 1.7 min to ski down a
1.67 km slope.
Answers
Answer:
103
Explanation:
do not listen to the haters
The _____________ is similar to a vacumn cleaner because it cleans up cell waste.
a
endoplasmic reticulum
b
lysosome
c
mitochondria
d
cell wall
Answers
B. Lysosome
Which part of project management involves determining possible risks?
Answers
Answer:
Resources
Explanation:
Answer:
Explanation:
M
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!!!!!!!!!!!
Answers
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
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.
Answers
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.
:answer question number 5
Answers
Answer:
it is simple true and thanks for point
Answer:
True
Explanation:
TRUST:)
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
Answers
Explanation:
i think the answer might be D
Which of the following are soluble in water: salt, gravel, or pepper
Answers
Atoms and ions are all the same.
Answers
Answer:
Yes they are
Explanation:
What human activity has caused the Increase of CO2 in the atmosphere?
Answers
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
Answers
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:
8. Which type of element requires the least amount of energy to remove an electron?
Answers
Answer:
nonmetals
Explanation:
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
Answers
(?)Li2O + (?)H2O → (?)LiOH
what goes inside the question marks?
Answers
Answer:
(1)Li2O + (1)H2O → (2)LiOH
Hope this helps!
The Tissues of vascular Plants are organized into more complex structures that carry out a Variety of functions in the plant what structure is formed by a Group of tissues that work together to carry out a Specific function
A) Cell
B) Organ system
C)Organism
D Organ
Answers
Answer:
D Organ
Explanation:
A group of tissues that work together to carry out a specific function is known as organ.
Life is organized into distinct levels. These organization makes it possible for certain cells which are the basic unit of life to carry out their respective function.
A group of cell that performs the same function are organized into tissues. A group of tissues that work together to carryout a specific function are known as organs. A group of organs that perform the same functions forms the organ systems.
As the complexity of an organism increases, so also is their organization of life.
The element with the smallest iconic radius in the alkaline earth metals is
Answers
Answer:
Metal.
Explanation:
Metal has the smallest iconic radius in the alkaline earth metal.
The number of atoms of an element in a chemical formula is given by the _________.
Answers
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:
please someone help me its due today thanks :D
Answers
Answer:
D
Explanation:
All of the above are great examples!
"Endothermic reactions are those which absorb heat during the reaction."
Please help this is chemistry.
Answers
Answer:
C
Explanation:
the rest are trends except for Electronegativity
______ have trees with cones.
A. temperate rainforests
B. boreal forests
C. tropical rainforests
D. temperate deciduous forests
Answers
Answer:
D.
Explanation:
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.
Answers
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.
Use the equation below to solve the problem that follows.
2H2 (g) + O2 (g) → 2H2O (g)
When David reacts 13.8 grams of hydrogen gas with excess oxygen, 87.0 grams of water are formed. Calculate his percent yield of water.
Answers
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]