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
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
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
?
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
Which refers specifically to a heated solution that holds more dissolved solution than it can hold at a lower temperature? supersaturated undersaturated heterogeneous homogeneous
Answer:
A. Supersaturated
Explanation:
i got it right on edge 2021
The heated solution that holds more dissolved solution than it can hold at a lower temperature is supersaturated solution. Therefore, option A is correct.
What is supersaturated solution ?A solution that contains more solvent than the typical amount that can dissolve at a specific temperature is said to be supersaturated. By introducing a tiny solute crystal known as a seed crystal, the excess dissolved solvent in a super-saturated solution can begin to recrystallize.
A solution that contains more solvent than the typical amount that can dissolve at a specific temperature is said to be supersaturated. A solution is considered supersaturated if it contains more solute than is necessary to saturate it.
A solution that contains more solute than it can hold at a specific temperature is said to be supersaturated. Usually, raising a solution's temperature causes more particles to dissolve, increasing the solute concentration.
Thus, option A is correct.
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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:
Sulphuric acid, also called ‘king of chemicals' has the formula H2SO4. Its appearance is different from that of hydrogen and sulphur. Give two other reasons why sulphuric acid is a compound and not a mixture.
Explanation:
Before proceeding to answering the question, we have t understand what we mean by both mixture and compound.
A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions and colloids.
A compound on the other hand is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds.
The two other reason why H2SO4 is a compound and not a mixture are;
1) The components which are Hydrogen, Sulphur and Oxygen cannot be separated by physical means.
2) It has a constant melting and boiling point.
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:
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.
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.
How much water should be added to 12 ml of alcohol to obtain 12% alcohol solution?
Answer:
88 mL of water.
Explanation:
Data obtained from the question include the following:
Volume of alcohol = 12 mL
Percentage of alcohol = 12%
Volume of water =..?
We can thus, obtain the volume of water needed to make 12% of the alcohol solution as follow:
Percentage of the solution = 100%
Percentage of alcohol = 12%
Percentage of water =?
Percentage of water = percentage of solution – percentage of alcohol
Percentage of water = 100 – 12
Percentage of water = 88%
Since 12% of alcohol is equivalent to 12 mL of alcohol, therefore 88% of water will also be equivalent to 88 mL.
Therefore, 88 mL of water is needed to make 12% of alcohol.
Which will change will cause the gravitational force between a baseball and a soccerball
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 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".
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
what's love like? what feels are involved?
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.
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
Name one way chemicals can help the environment
Energy storage and transport. Chemical energy transport.
Answer:
to clean the water
Explanation:
Determine the net iconic equation for the following chemical reaction: HCl(aq) + NH4OH(aq)———-> NH4Cl(aq) + H2O(I) Hint: HCl(aq) is strong acid NH4OH(aq) is a weak base
Answer : The net ionic equation will be,
[tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]
Explanation :
In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
The given balanced ionic equation will be,
[tex]HCl(aq)+NH_4OH(aq)\rightarrow NH_4Cl(aq)+H_2O(l)[/tex]
The ionic equation in separated aqueous solution will be,
[tex]H^+(aq)+Cl^-(aq)+NH_4^+(aq)+OH^-(aq)\rightarrow H_2O(l)+NH_4^+(aq)+Cl^-(aq)[/tex]
In this equation, [tex]NH_4^+\text{ and }Cl^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]
How do you find the amount of electrons for any element?
Answer:
If you know the number of protons and neutrons you have to simply subtract the number of neutrons by number of protons the answer will be number of neutron
Explanation:
Answer:
We can find the amount of electrons through its Atomic number and with the help of electronic configuration
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]
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.
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.
Describe how u would separate a mixture of salt , sand and iodine into different components. please help i will give a brainliest for this . PLEASE HELP?
to remove iodine sublime
to remove sand filter
to remove water evaporate
Explanation:
1. put the mixture in a beaker
2.Heat the mixture using a watch glass filled with cold water, the iodine will sublime at the base of the watch glass.
3.Add water to sand and salt. Stir for salt to diffuse in the water
4.Filter sand from the solution using a filter paper
5.evaporate the remaining water to remain with Salt crystals.
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.
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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:
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
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.
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A drug problem can quickly consume A)a small portions of a person income B)the bulk of a person income C)a person excess income
Answer:
b
Explanation:
a drug problem consumes the bulk of a persons income because drugs are expensive to buy
A drug problem can quickly consume the bulk of a person income
What is a drug problem?A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drug abuse or substance abuse refers to the use of certain chemicals for the purpose of creating pleasurable effects on the brain.
Drug use can have significant and damaging short-term and long-term effects. Taking some drugs can be particularly risky, especially if you take high doses or combine them with other drugs or alcohol.
People of any age, sex or economic status can become addicted to a drug. Certain factors can affect the likelihood and speed of developing an addiction.
The best way to prevent an addiction to a drug is not to take the drug at all. If your doctor prescribes a drug with the potential for addiction, use care when taking the drug and follow the instructions provided by your doctor. Thus you can save your income.
The correct answer is option B.
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