Answer:
When limestone is heated strongly, the calcium carbonate it contains absorbs heat (endothermic ) and decomposes to form calcium oxide. Calcium oxide (also known as quicklime) is a key ingredient in the making of cement and is also used to make certain types of plaster.
Explanation:
Limestone heated
When limestone is heated strongly, the calcium carbonate it contains absorbs heat (endothermic ) and decomposes to form calcium oxide. ... Calcium oxide (also known as quicklime) is a key ingredient in the making of cement and is also used to make certain types of plaster.
Burning Limestone
Burning limestone, which is calcium carbonate, gives you quick lime, calcium oxide. Mixed with water this produces slaked lime, calcium hydroxide. ... This is soft when first mixed, but with time absorbs carbon dioxide from the atmosphere and hardens as it reverts back to calcium limestone.
Limestone exposed to heat and pressure.
Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. ... Under the conditions of metamorphism, the calcite in the limestone recrystallizes to form a rock that is a mass of interlocking calcite crystals.
HELP PLEASE ||Suppose you add water to a 6 g of sugar to make a solution with a concentration of 3 g/L. What is the total volume of the solution?
Answer:
2 L
Explanation:
Divide the mass by the concentration to find the volume.
(6 g)/(3g/L) = 2 L
According to the concept of solubility, in order to make solution of sugar the total volume of solution is 2 g/L.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
In order to calculate total volume of solution divide mass/ concentration that is 6/3=2 g/L.
Thus, the total volume of the solution is 2 g/L.
Learn more about solubility,here:
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write an ionic half equation for the formation of hydrogen during this electrolysis
Answer:
A half-equation shows you what happens at one of the electrodes during electrolysis. Electrons are shown as e-. A half-equation is balanced by adding, or taking away, a number of electrons equal to the total number of charges on the ions in the equation.
When positive metal ions (cations) arrive at the negative electrode (the cathode), they gain electrons to form neutral metal atoms. This is called reduction. For example:
Pb2+ + 2e- → Pb
When negative non-metal ions (anions) arrive at the positive electrode (the anode), they lose electrons to form neutral atoms or molecules. This is called oxidation. For example:
2Br- → Br2 + 2e-
Writing half equations
Cations go to the cathode. They need to gain enough electrons to make them neutral. So an Al3+ ion needs to gain three electrons:
Al3+ + 3e- → Al
Half-equations for non-metal anions are more difficult to balance. For example, chloride ions make chlorine gas. Most non-metal elements formed in electrolysis are diatomic molecules (eg Cl2). For example:
Cl- → Cl2
Add in two electrons to balance the charge so that both sides have the same charge. The two electrons need to go on the right-hand side, so that both sides have an overall charge of -2. For example:
2Cl- → Cl2 + 2e-
Although your question lacks some information a general answer is provided
The ionic half equation = [tex]2H^{+} (aq) + 2e^{-} ----> H_{2} (g)[/tex]
The formation of hydrogen takes place at the negative electrode in a cell and the ionic half reaction that shows the formation of the hydrogen gas at the electrode is written as :
[tex]2H^{+} (aq) + 2e^{-} ----> H_{2} (g)[/tex]
Ionic half equation is the representation of the chemical activity ( reaction ) occurring at one of the electrodes of a cell. to balance a half reaction we add or remove electrons equal to charges on the ions.
Hence the Ionic half equation for the formation of hydrogen during electrolysis is written as ; [tex]2H^{+} (aq) + 2e^{-} ----> H_{2} (g)[/tex]
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give an example of competition in an ecosystem
hbzjaj
Explanation:
competition for food
In a warehouse, the workers sometimes slide boxes along the floor to move them. Two boxes were sliding toward each other and crashed. The crash caused both boxes to change speed. Based on the information in the diagram, which statement is correct? In your answer, explain what the forces were like and why the boxes changed speed.
Box 1 has more mass than Box 2.
Box 1 and Box 2 are the same mass.
Box 1 has less mass than Box 2.
Answer:
Box 1 and Box 2 are the same mass.
Explanation:
Because they both change speed due to having the same mass!
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please help!! will give brainliest if u tell me how
Why does heat transfer from object to object?
Select one:
a.Heat transfers because of the temperature differences between objects
b.Heat transfers because of the mass difference between objects
c.Heat does not transfer between objects
d.Heat is energy so it moves
What is the answer?
Answer:
Option A
Explanation:
The atomic number is the number of protons in the nucleus of an atom.
Help please
what is the half-life of c-14 at 250g?
Answer:
5,730 years
hope im right
Explanation:
Its half-life is 5,730 years. How much of a 250g sample of carbon-14 will be left in 5,000 years?
HELPPPP!!!
Which element has the greatest atomic size?
a) Francium
b) Hydrogen
c) Rubidium
d) Sodium
Answer:
A. Francium
Explanation:
I'm not for sure but I believe this is correct. Hope it helps:)
HELP WITH THIS WORD PROBLEMStudents want to gather evidence for the claim that the number of atoms present before a chemical reaction is equal to the number of atoms present after the chemical reaction. They decide to react vinegar and baking soda in a sealed plastic bag. Which of the following would provide the evidence the students need?
The mass of the plastic bag, baking soda, and vinegar before the reaction was equal to the mass after the reaction.
Bubbles were produced during the reaction, which meant that a gas was being produced
.The plastic bag did not change in any way, indicating that it was not involved in the reaction.
The mass of the baking soda was exactly equal to the mass of the vinegar used to create the chemical reaction.
Is the fractional distillation of liquefied air a physical or chemical change?
Answer:
Physical Chanhe is the answer : )
what is change in science
Answer:
Scientific change is: "Any change in the scientific mosaic, i.e. a transition from one accepted theory to another or from one employed method to another. "
Explanation:
the reaction 2F2+ 2H2O + 4HF + 02 find the number of moles of oxygen produced from 10 moles of fluorine
Answer:
20 moles of Oxygen
Explanation:
2F2 + 2H20 -> 4HF + O2
We have 10 moles of fluorine. Based on the reaction equation, we see that:
n O2 = 2 * n F2 (n is the number of moles)
=> n O2 = 2 * 10 = 20 (moles)
Because of this, the number of moles of oxygen is 20 moles.
Which of the following is the chemical formula for an acid?
- NHO3 (aq)
- NaOH (aq)
- NH3 (g)
- HCl (g)
- SCl2 (g)
Why?
Answer:
NH3 and HCl
Explanation:
NH3 and HCl are acids because of their hydrogen ions. NHO3 and NaOH are bases (you can tell because they have an OH). I don't believe SCl2 is an acid or a base
Calculate the volume which 1.00 mole of a gas occupies at STP.
Answer:
22.4 L
Explanation:
A gas at STP will possess the following;
Pressure (P) = 1 atm
Temperature (T) = 273K
General gas constant (R) = 0.0821 Latm/molK
Using the general gas law formula to calculate the volume a gas of 1 mol will contain;
PV = nRT
V = nRT/P
V = 1 × 0.0821 × 273 ÷ 1
V = 22.41/1
V = 22.4 litres
Number 2 plssssssssssssssssssssssssssssssss
Answer:
Its located on North America
A closed gas system initially has volume and pressure of 6400mL and 1.49atm with the temperature unknown. If the same closed system has values of 657 torrs, 9660mL, and 2450C, what was the initial temperature in K?
Answer: The initial temperature was 588 Kelvin
Explanation:
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 1.49 atm
[tex]P_2[/tex] = final pressure of gas = 657 torr = 0.864 atm (760 torr = 1atm)
[tex]V_1[/tex] = initial volume of gas = 6400 ml
[tex]V_2[/tex] = final volume of gas = 9660 ml
[tex]T_1[/tex] = initial temperature of gas = ?
[tex]T_2[/tex] = final temperature of gas = [tex]245^0C=(245+273)K=515K[/tex]
Now put all the given values in the above equation, we get:
[tex]\frac{1.49\times 6400}{T_1}=\frac{0.864\times 9660}{515}[/tex]
[tex]T_1=588K[/tex]
The initial temperature was 588 Kelvin
5. Keratin and collagen are examples of *
li
Answer:
Structural proteins
Explanation:
Glad I could Help Pls Brainliest
write the electronic configuration of an Na+ and CL-1
Answer:
Na+ lost one electron: 1s2 2s2 2p6
Cl- gained an electron: 1s2 2s2 2p6 3s2 3p6
Explanation:
A swimmer is moving at a speed of 2.0 meters/second. How long will it take for the swimmer to go 100 meters?
How many moles of steam are produced when 5.74 moles of octane (C8H18) react?
Calculate the change in heat (Q) that occurs when 7.58grams of steam at 101°C cools to liquid water at 40°C. (cp = 4.184 J/g°C)
Answer:
Q = 19065.4 J
Explanation:
Q₁ = the required energy for phase change of H₂O from vapor to liquid
Q₁ = mass of H₂O * heat of vaporization
Q₁ = 7.58 g * 2260 J/g
Q₁ = 17130.8 J
Q₂ = energy required to cool the water fro 101°C to 40°C
Q₂ = mass of H₂O * specific heat of H₂O * ΔT
Q₂ = 7.58 × (4.184 J/gC) × (101 - 40)
Q₂ = 1934.6 J
Q = Q₁ + Q₂
Q = (17130.8 + 1934.6) J
Q = 19065.4 J
A teacher tells the student to dlaw the same wave with double the frequency, while keeping the amplitude the same. How would the student draw the new wave?
Answer:
A.
Explanation:
Frequency is how often one complete cycle or wave takes place. Amplitude is the height of the wave from the midpoint to the crest.
The new drawing should have twice as many waves in the same period of time, with the same height wave.
Answer:
A.)
Explanation:
Frequency is how often one complete cycle or wave takes place. Amplitude is the height of the wave from the midpoint to the crest.
The new drawing should have twice as many waves in the same period of time, with the same height wave.
Science question: Which beat summarized the scientific process that led to our current understanding of DNA?
1 each scientist made an important but unrelated contribution
2. Scientists built on the previous work of other scientists to make new discoveries
3 and 4 are too long
Answer:
2
Explanation:
in terms of cells, it exists from previous existing cells, that means scientist are built up by the work of other scientist
Answer:
the answer is B
Explanation:
40 points
I have 400 mL of a 0.2 M simple syrup solution (made up of just sugar and water) that I want to boil down to result in a solution with a concentration of 0.5 M. How many milliliters of water would I need to evaporate?
Answer:
2000ml
Explanation:
you multiple 400ml with 0.5 ml to get the required meter for the water that needs to be evaporated
answer pls ill give brainly
How is energy from the sun used as food energy by organisms in an ecosystem?
Energy from the sun is absorbed as heat by consumers.
Energy from the sun is absorbed by fungi, and it is then passed on to consumers.
Energy from the sun is converted into food energy by producers, which is then passed on to consumers.
Energy from the sun is converted into food by consumers, which is then passed on to producers.
Answer:
its absorbed by heat from consumers
Give me lil reasoning so I know your not lying for points
:(
(I’ll mark you as brainlister )
Answer:
C
Explanation:
An inverse relationship means that as one increases the other decreases. From the negative slope of this graph, you can tell that as volume increases, pressure decreases. If you look at the data point for 20 on the volume axis, it matches up with about 240 on the pressure axis.
Calculate the molarity of a solution containing 21.9g of MgCl, in enough water to
make a 750.mL solution.
Calculate the change in heat (Q) that occurs when 38.68grams of steam at 304°C cools to liquid water at 197°C. (cp = 4.184 J/g°C)
Answer:
Change in heat (Q) = -1.7316 x 10⁴
Explanation:
Given:
Mass m = 38.68 g
Change in temperature Δt = (197-304) = -107°C
Specific heat C = 4.184 J/g°C
Find:
Change in heat (Q)
Computation:
Change in heat (Q) = (C)(m)(Δt)
Change in heat (Q) = (4.184)(38.68)(-107)
Change in heat (Q) = -1.7316 x 10⁴
how do i make chrystals
Answer:
1. In the beaker, stir 1/2 cup of Epsom salts with 1/2 cup of very hot tap water for at least one minute. ...
2. Add a couple drops of food coloring if you want your crystals to be colored.
3. Put the beaker in the refrigerator.
4. Check on it in a few hours to see a beaker full of epsom salt crystals!
Explanation:
_Al + _Fe(NO3)2 -->_Fe + __Al(NO3)3