Answer: A. 1.07 x 10∧ -18 J
Explanation:
The energy can be calculated by using this relation; E = hc / ∧
Where E = energy
h = Planck's constant = 6.626 x 10-34joules
c = speed of light = 3.00 x 10∧8 m/s
∧ = wavelenght = 185 nm = 185 x 10∧ -9m
Therefore; E= hc / ∧
= (6.626 x 10-34 j/s) x ( 3.00 x 10∧8 m/s) / 185 x 10∧ -9m
= 1.987 x 10 ∧ -25 / 185 x 10∧ -9m
= 1.07 x 10∧ -18 J
CAn someone help me and give me an example of a process that you notice or use each day that obyes the law of conservation of mass and explain how this process work??? please answer I need a new example not burning fire or candle or paper different helppppppppppppppppppppppppppppppppppppppppp
Answer:
photosynthesis maybe
Explanation:
bare with me i may be wrong or i may be right it's been a while since i've been in a chem classroom. so basically during photosynthesis a plant is taking the energy from the sun, H2O, and CO2, this ends up being like 6CO2 + 6H20 + (energy), and it converts this energy to glucose (→ C6H12O6 + 6O2 ) so the energy is never used up in this process it is merely changed. i don't really know but i hope it at least helps some
A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion. B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion. C. If Assertion is true statement but Reason is false. D. If Assertion is false and Reason is true i Assertion: .Burning of magnesium ribbon produce whitish powder called magnesium oxide. Reason : Magnesium is generally cleaned by rubbing it on sand paper
Answer:
C. If Assertion is true statement but Reason is false.
Explanation:
The burning of magnesium in air produces magnesium oxide as shown by the equation;
2Mg(s) + O2(g) -----> 2MgO(s)
The magnesium oxide solid is recovered as a white ash. This is a typical example of an oxidation reaction which is also a combustion reaction.
The reason has nothing at all to do with the assertion hence the answer given.
Magnesium oxide is basic just like the oxides of other metals and dissolves in water to yield an alkali.
Answer:
Answer:
C. If Assertion is true statement but Reason is false.
Explanation:
The burning of magnesium in air produces magnesium oxide as shown by the equation;
2Mg(s) + O2(g) -----> 2MgO(s)
The magnesium oxide solid is recovered as a white ash. This is a typical example of an oxidation reaction which is also a combustion reaction.
The reason has nothing at all to do with the assertion hence the answer given.
Magnesium oxide is basic just like the oxides of other metals and dissolves in water to yield an alkali.
Explanation:
Calcium (Ca) has an atomic number of 20. It can form an ion by losing 2
electrons. What would its charge be?
A. 18
B. 22
C. 2+
D. 2-
Answer:
2+
Explanation:
Apex lolz
Aqueous hydrobromic acid will react with solid sodium hydroxide to produce aqueous sodium bromide and liquid water . Suppose 34. g of hydrobromic acid is mixed with 11.4 g of sodium hydroxide. Calculate the maximum mass of water that could be produced by the chemical reaction
Answer:
5.13g of H2O.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
HBr(aq) + NaOH(aq) —> NaBr(aq) + H2O(l)
Next, we shall determine the masses of HBr and NaOH that reacted and the mass of H2O produced from the balanced equation.
This is illustrated below:
Molar mass of HBr = 1 + 80 = = 81g/mol
Mass of HBr from the balanced equation = 1 x 81 = 81g
Molar mass of NaOH = 23 + 16 + 1 = 40g/mol
Mass of NaOH from the balanced equation = 1 x 40 = 40g
Molar mass of H2O = (2x1) + 16 = 18g/mol
Mass of H2O from the balanced equation = 1 x 18 = 18g
Thus, from the balanced equation above,
81g of HBr reacted with 40g of NaOH to produce 18g of H2O.
Next, we shall determine the limiting reactant. This is illustrated below:
From the balanced equation above,
81g of HBr reacted with 40g of NaOH.
Therefore, 34g of HBr will react with = (34 x 40)/81 = 16.79g of NaOH.
From the calculations made above, we can see that it will take a higher mass (i.e 16.79g) of NaOH than what was given (i.e 11.4g) to react completely with 34g of HBr.
Therefore, NaOH is the limiting reactant and HBr is the excess react.
Finally, we can determine the maximum mass of H2O produced as shown below.
In this case the limiting reactant will used because it will produce the maximum mass of H2O since all of it is consumed in the reaction.
The limiting reactant is NaOH and the maximum mass of H2O produced can be obtained as follow:
From the balanced equation above,
40g of NaOH reacted to produce 18g of H2O.
Therefore, 11.4g of NaOH will react to produce = (11.4 x 18)/40 = 5.13g of H2O.
Therefore, the maximum mass of H2O produced from the reaction is 5.13g.
Use enthalpies of formation to determine the ΔHreaction for the reaction
CaCl2(s)---> CaCl2(aq).
Answer:
The enthalpy is increased by the increased heat of the reaction.
Explanation:
In this reaction, as the transition from solid to liquid state, enthalpy increases, that is, the heat applied to change its state is greater and this increases, reaching a mayor disorder.
If the reaction increases its heat, and a liquid state passes, the enthalpy increases, therefore the disorder also and the entropy will also be increased.
hurry I'm on a timer
Which term describes erosion?
O creates small particles
O hardens rock fragments
O transports solid materials
O dissolves rock components
Answer:
transports solid materials
Explanation:
Erosion is a process where solid materials are transported by natural forces such as wind or water.
Answer: c
Explanation:
Hi does anyone know how to do question 4?
Please show working out thanks.
answer:
a)1.274 g b) 0.013 mole
Explanation:
a) Mass of 1 mol of CuSo4. 5H20=
[tex]63 + 32 + (16 \times 4) + (7 \times 1) + (16 \times 5)[/tex]
=246g
no. moles of CuSo4. 5H2O=
[tex] \frac{mass}{mass \: of \: 1mole} [/tex]
so moles
=
[tex] \frac{3.14}{246} [/tex]
0.013 mole
in the equation
1 mole of sulphuric acid reacts to form 1 mole of CuSo4.5H2O
in other words
0.013 mole of sulphuric acid reacts to form 0.013 mole of CuSo4.5H2O
so mass of 1 mole (Mr) H2So4=
[tex](2 \times 1) + 32 + (16 \times 4)[/tex]
98g
mass of sulphuric acid= mole × mass of 1 mole
so mass= 0.013 × 98
1.274 g
b) In the equation
1 mole of sulphuric acid reacts to form 1 mole of copper(ll) oxide
in other words
0.013 mole of sulphuric acid reacts to form 0.013 mole of copper (ll) oxide
so 0.013 mole of copper(ll) oxide is reacted
Hope it helped and pls mark brainliest
Which missing item would complete this beta decay reaction?
Answer:
The answer is option A.Hope this helps you
Magnesium reacts with fluorine to form magnesium fluoride. Which diagram shows the correct arrangement of electrons in the product?
Answer:
Diagram B shows the correct arrangement of electrons in the product.
Magnesium reacts with fluorine to form magnesium fluoride two electrons of magnesium are transferred to the 2 atoms of fluorine and fluorine is the most electronegative element of the periodic table. Option C is correct.
What is electronegativity?Electronegativity is the tendency or power of an atom to attract the electrons from the metals they are mostly nonmetals and want to complete their octave too.
The most electronegative elements of the periodic table are oxygen, nitrogen, and fluorine, as they are always willing to complete the octave, and fluorine will take electrons from magnesium.
Therefore, Option C is correct if the 2 atoms of fluorine and fluorine are the most electronegative element of the periodic table. Magnesium reacts with fluorine to form magnesium fluoride two electrons of magnesium are transferred.
Learn more about electronegativity, here:
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how many atoms are in 2.10 g of K? molar mass of K=39.10g/mole.
Answer:
The answer is option BExplanation:
To calculate the number of atoms we must first calculate the number of moles
Molar mass = mass / number of moles
number of moles = mass / Molar mass
Molar mass (K) = 39.10mole
mass = 2.10g
number of moles = 2.10/ 39.10
= 0.0537mol
After that we use the formula
N = n × L
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10^23 entities
Number of K atoms is
N = 0.0537 × 6.02 × 10^13
N = 3.23×10^22 atoms of KHope this helps you.
Na + Cl2 ------> ?
what will be formed?
Answer:
2Na + Cl2 ------> 2NaCl
sodium + chlorine = sodium chloride (salt)
Answer:
Sodium chloride NaCl
Explanation:
NaCl will form.
2Na + Cl2 ----> 2NaCl
Each Na atom donates 1 electron from its outermost shell electron to each chlroine atom, so that Na can attain full outermost shell electrons (octet), where it is most stable. Na+ ion is formed after losing 1 electron.
Each chlroine atom gains 1 electron so that it can have 8 outermost shell electrons (stable). It becomes Cl- ion.
Combining Na+ and Cl-, NaCl is formed so that the net charge is 0. To balance the equation, since chlorine exists as diatomic molecule, 2 Na atom reacts with 1 chlorine molecule (2 chlorine atoms) to form 2 NaCl.
Which of the following describes what happens in a chemical reaction?
O A. Molecules change from one phase to another.
B. Molecules dissolved in solution are separated again.
O c. Chemical bonds are broken, and new ones are formed.
O D. Molecules mix without rearranging atoms.
Answer:
c. Chemical bonds are broken, and new ones are formed.
Explanation:
Hope this helps. :)
In a chemical reaction, chemical bonds are broken, and new ones are formed.
What is a chemical reaction?Chemical reactions are defined as reactions which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical reaction.
There are several characteristics of chemical reactions like change in color, change in state , change in odor and change in composition . During chemical reaction there is also formation of precipitate an insoluble mass of substance or even evolution of gases.
There are three types of chemical reactions:
1) inorganic reactions
2)organic reactions
3) biochemical reactions
During chemical reactions atoms are rearranged and changes are accompanied by an energy change as new substances are formed.
Learn more about chemical reactions,here:
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Which of the following is NOT an indicator of a chemical
reaction?
O A. Breaking into small pieces
OB. Producing a solid
OC. Changing color
OD. Producing light
Answer:OD. Producing light
Explanation:
Element Y has 8 shells.
The first three successive ionisation energies for element y increase gradually but the 4th ionisation energy increases sharply.
a)write electronic configuration for
elment Y & explain.
Answer:
electronic configuration of Y is 1s²2s²2p⁶3s²3px²3py²3pz¹
Explanation:
The electronic structure of chlorine is 1s²2s²2p⁶3s²3px²3py²3pz¹. The first two electrons are coming from pairs in the 3p levels and are therefore rather easier to remove than if they were unpaired
The contents of a Helium ballon are in which phase? A. Solid B. Plasma C. Liquid G. Gas
Consider the equation below.
Zn + H2SO4 → ZnSO4 + H2
The mole ratio of zinc to zinc sulfate is
Answer:
1:1
Explanation:
There is one mole of zinc (Zn) and one mole of zinc sulfate (ZnSO₄).
The mole ratio is 1:1.
Hope this helps.
Answer:
1:1
Explanation:
Based on the law of Conservation of Mass, what happens to the mass of a substance in a chemical change? A: the mass is always conserved B: The mass is either created or destroyed C: the reactant always has more mass D: the product always has more mass
Answer:
A.
Explanation:
The amount of mass always stays the same, matter cannot be created nor destroyed, it can only change forms. Thus, the answer is A.
In a chemical reaction the total mass of all the substances taking part in the reaction remains the same. Also, the number of atoms in a reaction remains the same. Mass cannot be created or destroyed in a chemical reaction.
I hope this helps..
Which of the following has the highest electromagnivity
Answer:
Where are the answer choices
?
How to get a catalyst back at the end of a chemical reaction?
Answer:
You should get the catalyst back already.
Explanation:
A catalyst shouldn't be used up during a chemical reaction. It is used to speed up a reaction, but it shouldn't disappear/be used up by a chemical reaction.
Anyone know how to answer this?
Answer:
i metal
ii nonmetal
iii metal
iv nonmetal
Explanation:
If you look up what the element of a heater is, you get a picture of some sort of rod. It's the heating element of the heater, and must be some type of metal to conduct electricity and warm up. Fishing rods are made of either fiberglass, graphite, or carbon fibre. These are nonmetals. In order for a lightning rod to conduct electricity and bring the lightning down to the ground, it has to be metal. You wouldn't want a metal oven mitt, as that would burn your hand.
What are the periodic trends of ionic radii? Check all that apply. Ionic radii tend to increase down a group. Ionic radii tend to decrease across a period. Anionic radii tend to increase across a period. Cationic radii tend to decrease across a period. Ionic radii increase when switching from cations to anions in a period.
Answer:
What are the periodic trends of ionic radii? Check all that apply.
*Ionic radii tend to increase down a group.
Ionic radii tend to decrease across a period.
Anionic radii tend to increase across a period.
*Cationic radii tend to decrease across a period.
*Ionic radii increase when switching from cations to anions in a period.
Answer:
- Ionic Radii Tend To Increase Down A Group.
- Cationic Radii Tend To Decrease Across A Period.
- Ionic Radii Increase When Switching From Cations To Anions In A Period.
Explanation:
i got it correct on edge
in Analytical chemistry laboratory. Nickle(ppm)in water sample estimated by two different students was as ,student 1 (25 24 24 24 24 28 26 ) and student 2 (24 25 24 24 25 25 ), if the true valude on Nickle in water was 20 ppm estimate the precision and accuracy of both students
Answer:
Answers are in the explanation
Explanation:
Precision and accuracy are both statistical concepts. Precision is about how close are the measured values to each other. Accuracy is closeness of the measured values to a specific value or reference value.
There are many ways to calculate precision and accuracy, one is stimating precision as Relative Uncertainty and accuracy as Relative Error.
Formulas are:
Relative Uncertainty: Standard desviation / Measured value.
Relative Error: Measured Value - Expected Value / Expected value
Measured value is the aveage of the values.
For student 1:
Mean = 25
Standard desviation = 1.5275
Relative Uncertainty: 1.5275 / 25
Relative Uncertainty: 0.061
Relative Error: 25 - 20 / 20
Relative Error: 0.25
For student 2:
Mean = 24.5
Standard desviation = 0.5477
Relative Uncertainty: 0.5477 / 24.5
Relative Uncertainty: 0.02
Relative Error: 24.5 - 20 / 20
Relative Error: 0.225
As the student 2 has a low Relative error and uncertainty, you can say student 2 is more accurate and precise
The table lists some organelles and functions. Only one pair is correctly matched. Functions of Organelles Organelle Function Chloroplast Stores water and waste materials Cell wall Supports cell membrane, maintains cell shape, and protects cell Cell membrane Breaks down waste materials and debris Vacuole Produces proteins for the cell Which organelle in the table is correctly matched with its function? chloroplast cell wall cell membrane vacuole plz help soon
The organelle that is matched correctly is the Cell Wall
The cell wall functions as a protective organelle as well as gives shape to the cell.
Functions of the cell wallThe cell wall is an organelle found in prokaryotic cells and plant cells.
Cell walls generally function to protect the cell by delimiting its surroundings the membrane from damage.
They also act as permeable structures to substances as well as give the respective cells their characteristic shapes.
More on cell walls can be found here: https://brainly.com/question/965751
little help plz? Determine which of the following is the correct equilibrium expression for the chemical reaction: Answer choices are below.
Answer:
Kc = [CaO] [O2] / [CaCO3]
Explanation:
Equilibrium constant, Kc is simply defined as the ratio of the concentration of products raised to their coefficient to the concentration of the reactants raised to their coefficient.
Thus, we can write the equation for the equilibrium constant, Kc for the reaction given in the question above as follow:
CaCO3(s) <==> CaO(s) + O2(g)
Kc = [CaO] [O2] / [CaCO3]
Calculate the number of grams of HNO3 which must be added to 31.5 g of H20 to prepare a 0.950 m solution.
Answer:
1.89g of HNO3
Explanation:
Data obtained from the question include:
Mass of water = 31.5 g
Molality of HNO3 = 0.950 m
Mass of HNO3 =.?
Next, we shall determine the number of mole of HNO3 in the solution.
Mass of water = 31.5 g = 31.5/1000 = 0.0315 Kg
Molality of HNO3 = 0.950 m
Number of mole of HNO3 =..?
Molality is simply defined as the mole of solute per unit kilogram of solvent (water) i.e
Molality = mole /kg of water
With the above formula, the mole of HNO3 can be obtained as follow:
Molality = mole /kg of water
0.950 = mole of HNO3 /0.0315
Cross multiply
Mole of HNO3 = 0.950 x 0.0315
Mole of HNO3 = 0.03 mole
Finally, we shall convert 0.03 mole of HNO3 to grams. This is illustrated below:
Molar mass of HNO3 = 1 + 14 + (16x3) = 63g/mol
Mole of HNO3 = 0.03 mole
Mass of HNO3 =..?
Mole = mass /molar mass
0.03 = mass of HNO3 /63
Cross multiply
Mass of HNO3 = 0.03 x 63
Mass of HNO3 = 1.89g
Therefore, 1.89g of HNO3 is needed to prepare the solution.
does anyone know how to do question nine if can you please show working out. thanks.
Answer:
A. 257600g (i.e 257.6 Kg) of CaO were produced.
B. 202400g (i.e 202.4 Kg) of CO2 were produced.
Explanation:
We'll begin by calculating the mass of CaCO3 present in 5×10² Kg of lime stone. This is illustrated below:
From the question given, the lime stone contains 92% of CaCO3.
Mass of CaCO3 = 92% x 5×10² Kg
Mass of CaCO3 = 92/100 x 5×10² Kg
Mass of CaCO3 = 460 Kg
Therefore, 460 kg of CaCO3 is present in the lime stone.
Next, we shall determine the mass of CaCO3 that was heated and the masses of CaO and CO2 produced from the balanced equation. This is illustrated below:
CaCO3(s) —> CaO(s) + CO2(g)
Molar mass of CaCO3 = 40 + 12 + (16x3) = 100g/mol
Mass of CaCO3 from the balanced equation = 1 x 100 = 100g
Molar mass of CaO = 40 + 16 = 56g
Mass of CaO from the balanced equation = 1 x 56 = 56g
Molar mass of CO2 = 12 + (2x16) = 44g/mol
Mass of CO2 from the balanced equation = 1 x 44 = 44g
Summary:
From the balanced equation above,
100g of CaCO3 were heated to produce 56g of CaO and 44g of CO2.
A. Determination of the mass of quick lime, CaO produced by heating 5×10² Kg of lime stone.
5×10² Kg of lime stone contains 460 Kg (i.e 460×10³ g) of CaCO3.
From the balanced equation above,
100g of CaCO3 were heated to produce 56g of CaO.
Therefore, 460×10³g of CaCO3 will be heated to produce = (460×10³ x 56)/100 = 257600g of CaO.
Therefore, 257600g (i.e 257.6 Kg) of CaO were produced.
B. Determination of mass of carbon dioxide, CO2 produced by heating 5×10² Kg of lime stone.
5×10² Kg of lime stone contains 460 Kg (i.e 460×10³ g) of CaCO3.
From the balanced equation above,
100g of CaCO3 were heated to produce 44g of CO2.
Therefore, Therefore, 460×10³g of CaCO3 will be heated to produce = (460×10³ x 44)/100 = 202400g of CO2.
Therefore, 202400g (i.e 202.4 Kg) of CO2 produced.
Simplify :: 3/8 + 7/2 + (-3/5) + 9/8 + (-3/2) + 6/5
Answer:
4.1/ [tex]\frac{41}{10}[/tex]
Explanation
Do the calculation carefully because this calculation has negative term.
I hope you will understand.
3/8 + 7/2 + (-3/5) + 9/8 + (-3/2) + 6/5
31/5+(-3/5)+(-3/2)
41/10
4.1
which statement describes suchitas final diagram
Answer:
Explanation:
The initial chemical energy is 50 J. The arrow for heat is the widest output arrow. The arrow for chemical energy is the shortest output arrow.
A 0.4647-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.01962 mol of CO2 and 0.01961 mol of H2O. The empirical formula of the compound was found to be C3H6O2
Answer:
The essence including its given problem is outlined in the following segment on the context..
Explanation:
The given values are:
Moles of CO₂,
x = 0.01962
Moles of water,
[tex]\frac{y}{2} =0.01961[/tex]
[tex]y=2\times 0.01961[/tex]
[tex]=0.03922[/tex]
Compound's mass,
= 0.4647 g
Let the compound's formula will be:
[tex]C_{x}H_{y}O_{z}[/tex]
Combustion's general equation will be:
⇒ [tex]C_{x}H_{y}O_{z}+x+(\frac{y}{4}-\frac{z}{2}) O_{2}=xCO_{2}+\frac{y}{2H_{2}O}[/tex]
On putting the estimated values, we get
⇒ [tex]12\times x=1\times y+16\times z=0.4647[/tex]
⇒ [tex]12\times 0.01962+1\times 0.03922+16\times z=0.4647[/tex]
⇒ [tex]0.27466+16z=0.4647[/tex]
⇒ [tex]z=0.01187[/tex]
Now,
x : y : z = [tex]0.01962:0.03922:0.01187[/tex]
= [tex]\frac{0.01962}{0.0118}:\frac{0.03922}{0.0188}:\frac{0.0188}{0.0188}[/tex]
= [tex]1.6:3.3:1.0[/tex]
= [tex]3:6:2[/tex]
So that the empirical formula seems to be "C₃H₆O₂".
in what type of molecule are london dispersion forces most important?
Answer:
Read below
Explanation:
The effects of London dispersion forces are most obvious in systems that are very non-polar (e.g., that lack ionic bonds), such as hydrocarbons and highly symmetric molecules such as bromine (Br2, a liquid at room temperature), iodine (I2, a solid at room temperature).