Answer:
decomposers
Explanation:
What is the pH of a neutral solution at 25ºC?
a. 14
b. 0
c. 1
d. 7
Answer:
d.7 is the correct answer
Electricity is possible because atoms release and absorb which sub-atomic particle?
Answer:
Electrons
Electric charge is carried by subatomic particles such as electrons and protons, which can be created and destroyed. For example, when particles are destroyed, equal numbers of positive and negative charges are destroyed, keeping the net amount of charge unchanged.
Redox reactions refer to a pair of reactions in which a particular oxidation is coupled to a corresponding reduction.
a. True
b. False
Answer:
A. True
Explanation:
You and your lab partner are asked to determine the density of an aluminum bar. The mass is known accurately (to four significant figures). You use a simple metric ruler to measure its dimensions and obtain the results for Method A. Your partner uses a precision micrometer and obtains the results for Method B.
Method A (g/cm3) 2.7 Method B (g/cm3) 2.703 2.701 2.705 5.811
The accepted density of aluminum is 2.702 g/cm 3 .
(a) Calculate the average density for each method.
Should all the experimental results be included in your calculations? If not, justify any omissions.
(b) Calculate the percent error for each method’s average value.
(c) Calculate the standard deviation for each set of data.
(d) Which method’s average value is more precise? Which method is more accurate?
Complete Question
You and your lab partner are asked to determine the density of an aluminum bar. The mass is known accurately (to four significant figures). You use a simple metric ruler to measure its dimensions and obtain the results for Method A. Your partner uses a precision micrometer and obtains the results for Method B.
Method A (g/cm3) 2.2,2.3,2.7,2.4 Method B (g/cm3) 2.703 2.701 2.705 5.811
The accepted density of aluminum is 2.702 g/cm 3 .
(a) Calculate the average density for each method.
Should all the experimental results be included in your calculations? If not, justify any omissions.
(b) Calculate the percent error for each method’s average value.
(c) Calculate the standard deviation for each set of data.
(d) Which method’s average value is more precise? Which method is more accurate?
Answer:
a)[tex]Ma_{avg}= 2.4g/cm^3[/tex]
[tex]Mb_{avg}=2701g/cm^3[/tex]
b)[tex]PE_a=7.5\%[/tex]
[tex]P.E_b=28.8 \%[/tex]
c) [tex]\sigma_A=0.35[/tex]
[tex]\sigma_B=0.0545[/tex]
d)Method A
Explanation:
From the question we are told that:
Method A Density values
2.7
Method B Density values
2.703,2.701,2.705,5.811
Density of aluminium [tex]p_d=2.702 g/cm^3[/tex].
a)
Generally the average density for each method is mathematically given by
Method A
[tex]Ma_{avg}= \frac{2.2+2.3+2.7+2.4}{4}[/tex]
[tex]Ma_{avg}= 2.4g/cm^3[/tex]
Method B
[tex]Mb_{avg}=\frac{2.703+2.701+2.705}{3}[/tex]
[tex]Mb_{avg}=2701g/cm^3[/tex]
b)
Generally the equation for percentage error [tex]PE[/tex] is is mathematically given by
percent error = (measured- real)/real *100
Given real = 2.702 g/ cm3
Method A =
[tex]PE_a=(2.5- 2.702)* \frac{100}{2.702}[/tex]
[tex]PE_a=7.5\%[/tex]
Method B =
[tex]PE_b=( 3.481- 2.702)*\frac{100}{2.702}[/tex]
[tex]P.E_b=28.8 \%[/tex]
c)
Generally the standard deviation [tex]\sigma[/tex] for each method is mathematically given by
Method A
[tex]\sigma=\sqrt{\frac{\sum(x-a)^2}{N} }[/tex]
[tex]\sigma=\sqrt{\frac{0.25+0.16+0+0.09}{4} }[/tex]
[tex]\sigma_A=0.35[/tex]
Method B
[tex]\sigma=\sqrt{\frac{\sum(x-a)^2}{N} }[/tex]
[tex]\sigma=\sqrt{\frac{0.000001+0.00000+0.000009+0.011881}{4} }[/tex]
[tex]\sigma_B=0.0545[/tex]
d)
Therefore with lower percentage error the method who's average value is more precise is
Method A
How many moles are there in 87.2 g of zinc fluoride?
Answer:
what I got was 0.8435160945347224 moles
Identify the Lewis acid in this balanced equation: SnCl4 + 2Cl− → SnCl62−
Answer:
The answer is SnCI4.
Explanation:
Answer:
it is a
cause it is and cause i'm right
What is neutralisation reaction? Give an example with reaction involved. State two uses of neutralisation reaction in everyday life.
Answer:
neutralization reaction is when an acid and a base react to form water and salt and involves the combination of hydrogen ions and hydroxyl ions to generate water. The neutralization of a strong acid and strong base has a pH equal to 7.
1. A sample of gas was compressed at 35 °C from a volume of 300.0 mL to a volume
of 100.0 mL where its pressure was found to be 30.0 mm Hg. What was the original
pressure of the gas, if there was no change in temperature? Type in your numerical
answer in the textbox. You may type in your work or upload a picture of it using the
"add file" button below the textbox.
Answer:
10 mm Hg
Explanation:
We can solve this problem using Boyle's law, which states that at a constant temperature:
P₁V₁=P₂V₂The subscript 1 stands for the initial conditions and 2 for the final conditions.
In this case:
P₁ = ?V₁ = 300.0 mLP₂ = 30.0 mm HgV₂ = 100.0 mLWe input the data:
P₁ * 300.0 mL = 30.0 mm Hg * 100.0 mLAnd solve for P₁:
P₁ = 10 mm HgThe colder parts of the surface of Pluto have a temperature of –382°F. What is this temperature in Celsius?
How does the ozone layer work?
Answer:
The atmosphere acts like a multi-layer shield that protects Earth from dangerous solar radiation. ... The stratospheric ozone layer absorbs ultraviolet (UV) radiation, preventing dangerous UV rays from hitting Earth's surface and harming living organisms. (Just look it up)
Explanation:
I hope this helps!
Imagine that you have an ideal gas in a 5.80 L container, and that 2950 molecules of this gas collide with a square-centimetre area of the container at any given instant.
If the volume is increased to 46.4 L at constant temperature, how many collisions will occur per square centimetre of this larger container?
Answer:
23,600 collisions.
Explanation:
Hello there!
In this case, according to the Avogadro's law, which help us to understand the molecules-volume relationship as directly proportional:
[tex]\frac{molecules_2}{V_2}=\frac{molecules_1}{V_1}[/tex]
It is possible for us to compute the collisions once the volume is increased as shown below:
[tex]molecules_2=\frac{molecules_1V_2}{V_1}\\\\molecules_2=\frac{2950*46.4L}{5.80L}\\\\molecules_2=23600[/tex]
Which means 23,600 collisions will occur per square centimeter.
Regards!
True or False?
A hydrogen bond is an attraction between molecules containing hydrogen that is not considered a true chemical bond.
Answer:TRUE
Explanation:
A hydrogen bond is the electromagnetic attraction created between a partially positively charged hydrogen atom attached to a highly electronegative atom and another nearby electronegative atom. A hydrogen bond is a type of dipole-dipole interaction; it is not a true chemical bond.
If the pH of a solution is 1.5 , calculate [H^ + ] .
Help plz??
Answer: Thus hydrogen ion concentration is 0.031622777
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
[tex]pH=-\log [H^+][/tex]
Putting in the values:
[tex]1.5=-\log[H^+][/tex]
[tex][H^+]=10^{-1.5}=0.031622777[/tex]
Thus hydrogen ion concentration is 0.031622777
Predict the products for the reaction shown in the picture.
Fe(s) + CuCrO4(aq) —>
Answer:
After checking many websites as well
I haven't seen any answer for this reaction
While I found answers or other reactions
Therefore I think this reaction cannot occur
Please mark my answer as brainliest if you feel I helped you in any way :)
Two students come up with an idea they think will save time: We just used the fast titrations. You can stop the video when the solution turns pink. We know that when the solution turns pink, the titration is complete, so we just read the volume from the burette as soon as it turns pink. This is faster than going through all the shorter videos and works just as well. Is this method just as accurate as using the slow titrations
Answer:
Yes.
Explanation:
Yes, this method is accurate just as the slow titration because in both type of titrations we want to measure the point at which the indicator change the colour of the solution. Both fast and slow titrations are the same in their function i.e. both tell us the point or the amount at which the indicator change the colour of the solution so we can conclude from this discussion that fast titration gives the same result just as the slow titration.
Eaterfication experiment
Answer:
Do you mean Esterification experiment?
Explanation:
A cylinder of compressed gas rolls off a boat and falls to the bottom of a lake. Eventually it rusts and the gas bubbles to the surface. A chemist collects a sample of the gas with the idea of trying to identify the gas. The wet gas collected occupies a volume of 283 mL at a pressure of 745 torr and temperature of 28.0oC. The vapor pressure of water at 28.0oC is 0.0372 atm. 1. Calculate the volume (L) that the gas occupies after it is dried (the water vapor removed) and stored at STP. Tries 0/99 The mass of the dry gas is 905 mg. A fragment of the tank indicates that the gas is a monoatomic element. 2. Write out the full name of the gas.
Answer:
See explanation
Explanation:
From the information given;
We convert the pressure from torr to atm as follows;
745 torr * 1 atm/760 torr = 0.98 atm
Initial pressure P1 = 0.98 atm - 0.0372 atm = 0.9428 atm
Initial volume V1= 283 mL
Initial temperature T1 = 28.0oC + 273 = 301 K
Final volume V2 = ??
Final Temperature T2 = 273 K
Final pressure P2 = 1 atm
From the general gas equation;
P1V1/T1 = P2V2/T2
P1V1T2 = P2V2T1
V2 = P1V1T2/P2T1
V2 = 0.9428 * 283 * 273/1 * 301
V2 = 241.99 mL or 0.24 L
If 1 mole of gas occupies 22.4 L
x moles of gas occupies 0.24 L
x = 1 mole * 0.24 L/ 22.4 L
x = 0.0107 moles
But number of moles = mass/molar mass
molar mass = mass/number of moles
molar mass = 905 * 10^-3g/0.0107 moles
molar mass = 84 g/mol
The monoatomic gas is Krypton
How many grams (g) are in 4.00 moles of Carbon (C) ?
Answer:
There are 36 grams in 4.00 moles of Carbon.
Explanation:
In order to convert from moles of a substance into grams of the same substance, we need to use the substance's molar mass.
That means that in this case we use the molar mass of Carbon:
4.00 mol * 12 g/mol = 36 gThus, there are 36 grams in 4.00 moles of Carbon.
that create stars, scientists understand more and more about how the universe came into existence. The ne
little green men up in space, think about all the great astronomers who have studied the night sky in search
Question 1
Using the information in the passage, rank the types of galaxies by their ability to form new stars, from most to
least activity
.
Elliptical, spiral, irregular
Irregular, elliptical, spiral
Spiral, irregular, elliptical
Irregular, spiral, elliptical
Son
Answer:
i would have to read the artical but i would say the first one
Explanation:
pls help What are the benefits and limitations of scientific experiments and investigations?
Answer please correctly
Answer:
the correct answere to that is q
Answer:
D.
Explanation:
What type of cloud is associated with a warm front
The Haber Process synthesizes ammonia at elevated temperatures and pressures. Suppose you combine 1580 L of nitrogen gas and 4595 L of hydrogen gas at STP, heat the mixture to run the reaction, then isolate the ammonia from the reaction mixture. What volume of NH₃ in liters, measured at STP, would be produced? Assume the reaction goes to completion.
N₂ (g) + 3 H₂ (g) → 2 NH₃ (g)
Answer:
The volume of reactant measured at STP left over is 409.9 L
Explanation:
Which of the following equations follows the law of conservation of mass?
Answer:
[tex]\boxed {\boxed {\sf 2 K + Cl_2 \rightarrow 2KCl}}[/tex]
Explanation:
The law of conservation of mass states that mass cannot be created or destroyed. The mass of the reactants must equal the mass of the products. Basically, the number of atoms at the beginning is the same as the end.
Count up the atoms on the left and right sides of the arrow. Remember to account for coefficients and subscripts.
1. 2Fe+3O₂⇒Fe₂O₃
Right: 2Fe + 3O₂
2 Fe atoms and 6 O atoms (3 * 2 per molecule)Left: Fe₂O₃
2 Fe atoms and 3 O atoms NOT balanced2. 2H₂+ O₂ ⇒ 2H₂O₂
Right: 2H₂+O₂
4 H atoms (2 * 2 per molecule) and 2 O atomsLeft: 2H₂O₂
4 H atoms and 4 O atoms (2*2 per molecule for both) NOT balanced3. 2K+Cl₂⇒ 2KCl
Right: 2K + Cl₂
2 K atoms and 2 Cl atomsLeft: 2KCl
2 K atoms and 2 Cl atoms This equation is balanced, but we should still check the last choice to ensure we are correct.4. C+O₂ ⇒ 2CO
Right: C+O₂
1 C atom and 2 O atomsLeft: 2CO
2 C atoms and 2 O atoms NOT balancedThe only balanced equation that follows the conservation of mass is choice 3: 2K+Cl₂ ⇒2KCl
Sulfuric acid (H₂SO₄), is formed when sulfur dioxide (SO₂) reacts with oxygen and water. Using the balanced chemical reaction above, how many moles of H₂SO₄ are produced from 8.5 moles of SO₂?
Answer:
8.5 mol H₂SO₄
Explanation:
It seems the balanced reaction the problem is referring to is absent, however the description matches the following balanced reaction:
2SO₂ + O₂ + 2H₂O → 2H₂SO₄Now we can convert 8.5 moles of SO₂ into moles of H₂SO₄, using the stoichiometric coefficients of the balanced reaction:
8.5 mol SO₂ * [tex]\frac{2molH_2SO_4}{2molSO_2}[/tex] = 8.5 mol H₂SO₄Water is amphoteric. If it reacts with a compound that is a stronger acid than itself, water acts as a
Answer:
Water acts as a base in the presence of a strong acid
Explanation:
Water,being an amphoteric compound, can act both as an acid and as a base.
In the presence of an acid , water acts as a base but in the presence of a base, water acts as an acid.
The following containers have the same number of molecules and temperature. Which container has the most collisions?
Answer:
Container 1 I think.
The containers have the same number of molecules and temperature. The container 1.
What is collision?Collision is the encounter between two particles or object. There are three type of collision: perfectly elastic collision, inelastic collision, perfectly inelastic collision.
Container 1 is smallest, so there will be less distance between the molecules, so they will collide most.
Thus, the containers have the same number of molecules and temperature. The container 1.
Learn more about collision
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Which of the following elements will form positive ions? Check all
that apply.
Na
z
Cu
Br
Answer:
cu and Na
Explanation:
When an atom losses electrons this results in a positive charge. A positively charged ion is called a cation.
Sodium and copper will form positive ions. Sodium is a monovalent cation while copper is a divalent cation.
What are positive ions?The ions which contain a positive charge it is called positive ions. The atomic number of sodium is 11. It contains (2, 8, 1) electrons. When it loses it's one electron it will be a positive ion.
Copper has valence electrons. When it loses its two valence electrons it will be a copper ion. There are two types of ions such as positive ions and negative ions.
Small molecules that have acquired a positive charge are known as positive ions. Positive ions are the predominant type of air pollution, including hazardous substances, pollen, mold, pet dander, and other dangerous chemicals.
Therefore, Sodium and copper will form positive ions. Sodium is a monovalent cation while copper is a divalent cation.
To learn more about positive ions, refer to the link:
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A 20 g granite boulder absorbs 300.2 Joules of energy from the Sun, resulting in its temperature
changing. Calculate this temperature change
Answer:
19 °C
Explanation:
Step 1: Given and required data
Mass of granite (m): 20 gHeat absorbed (Q): 300. 2 JSpecific heat capacity of granite (c): 0.790 J/g.°CStep 2: Calculate the temperature change (ΔT)
We will use the following expression.
Q = c × m × ΔT
ΔT = Q/c × m
ΔT = 300.2 J/(0.790 J/g.°C) × 20 g = 19 °C
Which of the following correctly shows a synthesis reaction involving potassium?
A. Br2 + 2KI → I2 + 2KBr
B. 4K + O2 → 2K2O
C. 2KClO3 → 2KCl + 3O22KClO3 → 2KCl + 3O2
D. 2K2O → 4K + O22K2O → 4K + O2
Answer:
B. 4 K + O₂ → 2 K₂O
Explanation:
Which of the following correctly shows a synthesis reaction involving potassium?
A. Br₂ + 2 KI → I₂ + 2 KBr
No, this is a single displacement reaction, in which Br displaces I from its salt.
B. 4 K + O₂ → 2 K₂O
Yes, this is a synthesis reaction, in which 2 elements combine to form a compound.
C. 2 KClO₃ → 2 KCl + 3 O₂
No, this is a decomposition reaction, in which a big substance decomposes into smaller ones.
D. 2 K₂O → 4K + O₂
No, this is a decomposition reaction, in which a big substance decomposes into smaller ones.