Describe the energy transfers and transformations
that occur when a person rides a bicycle. Make sure to identify each example as an energy transfer or an energy transformation.
Answer:
Explanation:
When you are pedaling the bike, it is transforming chemical energy, supplied by the breakdown of the food you eat (any food), into mechanical energy to turn the pedals (energy we produce). The chemical energy is potential and the mechanical energy is kinetic.
Hope this helps :)
A chemist reacts 35 g of MgCl, with excess KOH according
to the reaction below. How much Mg(OH)2 would be
produced if the reaction goes to completion?
MgCl2 + 2KOH – Mg(OH)2 + 2KCI
Answer:
Mass = 21.58 g
Explanation:
Given data:
Mass of MgCl₂ = 35 g
Mass of Mg(OH)₂ produced = ?
Solution:
Chemical equation:
MgCl₂ + 2KOH → Mg(OH)₂ + 2KCl
Number of moles of MgCl₂:
Number of moles = mass/molar mass
Number of moles = 35 g/ 95.2 g/mol
Number of moles = 0.37 mol
now we will compare the moles of MgCl₂ and Mg(OH)₂
MgCl₂ : Mg(OH)₂
1 : 1
0.37 : 0.37
Mass of Mg(OH)₂ :
Mass = number of moles × molar mass
Mass = 0.37 mol × 58.32 g/mol
Mass = 21.58 g
Electrons flowing through a wire can be compared to ___________ flowing through a hose. Once the flow of electrons or water is going, _______________, is performed.
Answer:
water, work
Explanation:
The flow of electros through a conductor is electric current. These electrons cannot be seen and so electric circuits can be used to model the arrangement and understand the process. Water flowing through pipes is a fitting mechanism that looks like the electrical circuit.
In this mechanism, the pipe is seen as the wire in the electric circuit while the pump is viewed as the battery. The pressure, like the voltage generated by the battery, comes from the pump and drives the water through the pipe.
A gas occupies 4.30 Liters at STP. What volume does it occupy at 2.56 atm and 302
Kelvin? Show all your work. .

Answer:
V₂ = 1.86 L
Explanation:
Given data:
Initial volume = 4.30 L
Initial pressure = 1 atm
Initial temperature = 273.15 K
Final temperature = 302 K
Final volume = ?
Final pressure = 2.56 atm
Solution:
According to general gas equation:
P₁V₁/T₁ = P₂V₂/T₂
V₂ = P₁V₁T₂ /T₁ P₂
V₂ = 1 atm ×4.30 L × 302 K / 273.15 K × 2.56 atm
V₂ = 1298.6 atm.L.K / 699.26 K.atm
V₂ = 1.86 L
An atom has three shells with 3 electrons in the last shell. This atom could be.....
O B
O Al
O Ga
O Si
Which is a gas at room temperature?
A) aluminum
B) nitrogen
C) potassium
D) sodium
Answer:
B) nitrogen
the Earth's atmosphere is mostly nitrogen
Bohr models show _________ while Dot Diagrams show _______ electrons only.
Answer:
Bohr models show the electrons in atoms are in orbits of differing energy around the nucleus while Dot Diagrams show the bonding in a small molecule only.
Explanation:
Metal X has a specific heat capacity of 0.982 Jg∙°C . If 525.0 g of Metal X increases in temperature from 32.00° C to 43.00° C, how much energy will be absorbed?
Answer:
Q = 5671.05 J
Explanation:
Given data:
Mass of metal = 525 g
Initial temperature = 32.0 °C
Fina temperature = 43.0 °C
Heat absorbed by metal = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
specific heat capacity of metal X = 0.982 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 43.00°C - 32.00°C
ΔT = 11.00°C
Q = 525 g × 0.982 J/g.°C × 11.00°C
Q = 5671.05 J
Compare and Contrast the two common forces of gravity and friction.
Answer:
Gravity always pulls objects such as a desk, book or person down. Thus, when you jump gravity causes you to land on the ground. Friction, however, doesn't pull objects down
need help with this please help.
Mg (50.0 g) and HCI (75.0 g) were added together to produce MgCl2 and H2
Mg + 2HCl → MgCl2 + H2
a) What mass of hydrogen gas produced in this reaction?
b) how much of the excess reactant is left over?
Answer:
Mass of hydrogen produced = 2.1 g
Mass of excess reactant left = 25.2 g
Explanation:
Given data:
Mass of Mg = 50.0 g
Mass of HCl = 75.0 g
Mass of hydrogen produced = ?
Mass of excess reactant left = ?
Solution:
Chemical equation:
Mg + 2HCl → MgCl₂ + H₂
Number of moles of Mg:
Number of moles = mass/molar mass
Number of moles = 50 g/ 24 g/mol
Number of moles = 2.1 mol
Number of moles of HCl:
Number of moles = mass/molar mass
Number of moles = 75 g/ 36.5 g/mol
Number of moles = 2.1 mol
now we will compare the moles of hydrogen gas with both reactant.
Mg : H₂
1 : 1
2.1 : 2.1
HCl : H₂
2 : 1
2.1 : 1/2×2.1 = 1.05 mol
HCl is limiting reactant and will limit the yield of hydrogen gas.
Mass of hydrogen:
Mass = number of moles × molar mass
Mass= 1.05 mol ×2 g/mol
Mass = 2.1 g
Mg is present in excess.
Mass of Mg left:
HCl : Mg
2 : 1
2.1 : 1/2×2.1 = 1.05
Out of 2.1 moles of Mg 1.05 react with HCl.
Moles of Mg left = 2.1 mol - 1.05 mol = 1.05 mol
Mass of Mg left:
Mass = number of moles × molar mass
Mass = 1.05 mol × 24 g/mol
Mass = 25.2 g
With carbon dioxide, what phase change takes place when pressure increases from 1 atm to 10 atm at -40C?
Answer:
See explanation
Explanation:
The phase changes of carbon dioxide is quite interesting. It is even more interesting that its phase change from gas to solid is dependent on pressure and temperature.
The triple point of CO2 is -56°C at 5.11 atm pressure. This implies that below 5.11 atm, liquid CO2 can not exist. In fact, at -78°C and 1 atm, CO2 is a solid.
Hence, when pressure increases from 1 atm to 10 atm at -40C, CO2 changes from liquid to gas.
all molecules are made of similar type of atom true or false
Answer:
False
Explanation:
Not all molecules are compounds, since some molecules, such as oxygen gas (above image of molecule of-O2) or ozone (O3), consist only of one element or type of atom. Water is also a molecule because it is made from atoms that have been chemically combined.
How many carbon atoms are in each mole of calcium carbonate?
Answer:
5 atoms are in each molecule of calcium carbonate
Name two metals which have a coating of another metal.
Answer:
Chromium is electroplated on other metals. 2. Gold is electroplated on other cheap metals.
Can somebody help me. Will mark brainliest.
Answer:
2.27%
Explanation:
The observed value of the boiling point = 71.8°C
The actual value of the boiling point = 70.2°C
We need to find the percentage error of the student's measurement. The percentage error in any value is given by :
[tex]\%=\dfrac{\text{calculated value-actual value}}{\text{actual value}}\times 100\\\\=\dfrac{71.8-70.2}{70.2}\times 100\\\\=2.27\%[/tex]
So, the required percentage error is 2.27%.
What are the disadvantages of the use of chemical fertilizers?
Answer:
1. chemical fertillizers encourage plant disease
2. chemical fertillizers affect micro-organism living in the soil.
Explanation:
What is meant by an acid and a base
Explanation:
Acid is Sour, sharp, or biting to the taste; tart; having the taste of vinegar.Base is any of a class of generally water-soluble compounds, having bitter taste, that turn red litmus blue, and react with acids to form salts.Hope it will help):)
Answer:
an acid is any hydrogen containing substance that. can donate protons.
a base is a molocule that is able to accept hydrogen ion from an acid
why does lowering the pressure cause a liquid to boil
Answer:This pressure is transmitted throughout the liquid and makes it more difficult for bubbles to form and for boiling to take place. If the pressure is reduced, the liquid requires less energy to change to a gaseous phase, and boiling occurs at a lower temperature
Explanation:
Atmospheric Pressure and Boiling
The pressure of gas above a liquid affects the boiling point. ... If the pressure is reduced, the liquid requires less energy to change to a gaseous phase, and boiling occurs at a lower temperature
Which of the following statements is/are correct?
I.
II.
Mass of 1 atom of Carbon-12 is equal to 1 amu
Mass of 4 atoms of Carbon-12 is equal to mass of 3 atoms of Oxygen-16
(A) Only I
(B) Only II
(C) Both I and II
(D) None of them
Answer:
The correct statement is;
(B) Only II
Explanation:
I) The atomic mass unit or amu which is also known as daltons which is defined as 1/12 × the mass of a carbon-12 atom, which is therefore, 1.660538921 × ⁻²⁴ grams
Therefore, the mass of 1 atom of carbon-12 = 12 amu
II) The mass of one mole of oxygen-16 is 16 grams while the mass of one mole of carbon-12 is 12 grams
The mass of 4 atoms of carbon 12 = 4 × 12 amu = 48 amu
The mass of 1 atom of oxygen-16 = 15.99491461956 amu
Therefore, the mass of 3 atoms of oxygen-16 = 3 × 15.99491461956 = 47.9847438587 amu ≈ 48 amu
Therefore only II is correct.
During the process of cellular respiration, water becomes oxygen.
True
False
Answer:
False
Explanation:
Please mark brainlliest if you want and mark 5 stars please. Thank you and have a good day.
Hello everyone! I have a question about science;
In a video game, a flying coconut moves at a constant velocity of 20 meters/second in a positive direction. The coconut hits an obstacle and moves in the opposite direction with a constant velocity of 10 meters/second. What’s the change in velocity of the coconut?
A.
-30 m/s
B.
-10 m/s
C.
10 m/s
D.
30 m/s
What is the number of electronsin hydrogen?
Answer:
1
Explanation:
What is the chemical formula for fluoride?
Answer:b
Explanation:
1) How many bonds can Sr atom form?
a) 5
c) 3
b) 4
d) 2
Answer:
the answer is C
Explanation:
it can form 3 bonds
PLEASE HELP!! A model of an atom is shown below. Which element is represented by this
model?
Answer:
Carbon
Explanation:
HELP PLEASE
Based on the organization of the Periodic Table of the Elements, what kind of bond does
chlorine form with both sodium and potassium?
A)ionic
B)metallic
© covalent
D)hydrogen
a) ionic
chlorine is present in top of group 17 and right of period 3 and
electronegativity(the tendency to gain electrons)
increases up the group and right the group.
so it has high tendency to form anion.
In the same way both Na and K are present up the group and left side and the tendency to lose electrons in both becomes high and they tend to form cation.
What are the series of steps that form oxygen atoms?
Answer:
2.5.2 Atomistic Configurations of Oxygen in Silicon Crystals
Oxygen atoms are incorporated in the silicon lattice on an interstitial position (denoted by Oi), where the oxygen atom sits in an almost bond-centered position between two adjacent Si atoms [101]. Several of the local vibration modes are infrared (IR) active. The predominant IR line at 1104/cm (at room temperature) was calibrated with respect to other analytical methods, such as gas fusion and several radioactive techniques, and is used as the standard method for the quantitative determination of the oxygen content in as-grown silicon crystals (as-grown silicon usually contains only a negligible amount of precipitated oxygen).
what do scientists use to classify substances that are either an acid or a base?
Answer:
They use the pH scale
Explanation:
The strong acid and strong base has high rate constant of dissociation. Weak acid and base are the one whose rate constant for the dissociation is low, they do not dissociate readily in water. Scientist use pH scale to classify substances that are either an acid or a base.
What are acid and base?Acid is a solution which releases H⁺ hydrogen ion when dissolved in water. Base are the solution which releases hydroxide ion OH⁻ ion when dissolved in water. . At room temperature pH scale is between 0 to 14. pH of neutral solution is 7.
The pH of acid is between 0-7 on pH scale. acid turns blue litmus paper to red. Acids have sour taste and corrosive nature. Mathematically the concentration of hydrogen ion can be calculated using this formula
Mathematically,
pH=-log[H⁺]
Therefore, scientist use pH scale to classify substances that are either an acid or a base.
To know more about acid and bases, here:
https://brainly.com/question/27228111
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Define the ground state of an atom
Explanation:
The nucleus of an atom is surround by electrons that occupy shells, or orbitals of varying energy levels. The ground state of an electron, the energy level it normally occupies, is the state of lowest energy for that electron. There is also a maximum energy that each electron can have and still be part of its atom.