Answer:
Fecal coliform increases the amount of organic substances in water and lowers the amount of dissolved oxygen, killing fish.
Explanation:
Fecal coliform are species of bacteria that are found in the intestine of warm-blooded animals like humans etc. Hence, they are released whenever they excrete feaces. Due to this reason, the presence of fecal coliform bacteria in a water body indicates fecal discharge into that water.
The presence of excessive fecal coliform in a water body increases the amount of organic substances in the water. These organic substances are decomposed by bacteria, which causes the oxygen present in the water body (dissolved oxygen) to deplete/decrease. The depletion of oxygen in the water threatens aerobic aquatic organisms e.g fishes and they ultimately suffocate and die.
which of the following shows how rate depends on concentrations of reactants?
Answer:
option c
Explanation:
Rate = k(A)¹(B)²
Answer:
c
Explanation:
a p e xxxxxxxxx
Which is the proper order for using a fire extinguisher? pull, aim, squeeze, sweep sweep, squeeze, aim, pull aim, pull, sweep, squeeze pull, sweep, aim, squeeze
Answer:
P.A.S.S
pull, aim, squeeze, sweep.
hope this answer correct (^^)..
Answer:
The proper way of using an extinguisher is:
pull, aim, squeeze and sweep.
Explanation:
P-pull
A-aim
S-squeeze
S-sweep
You can always use this to remember, okay.
Hope it helps.
Which of the following solute(s) would form an electrolytic solution in water? CH4, KI, fecl3
Answer:
kl
Explanation:
According to the concept of solubility and electrolysis , KI would form an electrolytic solution in water.
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.
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Which of the following observations would indicate that a material is a pure substance?
O It does not dissolve in water.
O It changes color after heating.
O It cannot be physically broken down into different types of atoms.
O It can be physically broken down into different types of molecules
Save and Fyit
Noy
Answer:
C. It cannot be physically broken down into different types of atoms.
Use the Trapezoid Rule to approximate the value of the definite integral
Answer:
7.0625
Explanation:
The trapezoidal rule ( this is an approximation ) tells you that the average of the left and right endpoints should be as follows,
[tex]\int _a^bf\left(x\right)dx\:\approx \frac{\Delta \:x}{2}\left(f\left(x_0\right)+2f\left(x_1\right)+...+2f\left(x_{n-1}\right)+f\left(x_n\right)\right)[/tex]
where [tex]\Delta \:x\:=\:\frac{b-a}{n}[/tex] ... at this point we can apply the Riemann Formula, in order to divide the interval 0 ≤ x ≤ 2 into n = 4 subintervals of length [tex]\:\Delta x=\frac{1}{2}\:[/tex].
[tex]x_0=0,\:x_1=\frac{1}{2},\:x_2=1,\:x_3=\frac{3}{2},\:x_4=2[/tex] ,
[tex]\frac{\Delta x}{2}=\frac{\frac{1}{2}}{2}=\frac{1}{4}[/tex]
= [tex]\frac{1}{4}\left(f\left(x_0\right)+2f\left(x_1\right)+2f\left(x_2\right)+2f\left(x_3\right)+f\left(x_4\right)\right)[/tex] - Let's calculate the sub intervals for each, substituting to receive our solution.
[tex]f\left(x_0\right)= 0[/tex] ( this is as 0⁴ is 0 )
[tex]2f\left(x_1\right)= 1/8[/tex] ( this is as [tex]2\left(\frac{1}{2}\right)^4=1/8[/tex] )
[tex]2f\left(x_2\right)=2[/tex] ( 2 [tex]*[/tex] 1⁴ is 2 )
[tex]2f\left(x_3\right)= 81/8[/tex] ( this is as [tex]2\left(\frac{3}{2}\right)^4 = 81/8[/tex] )
And finally [tex]f\left(x_4\right) = 16[/tex], as 2⁴ is 16. Therefore, let us plug in our solutions for each into the primary expression, and solve,
[tex]\frac{1}{4}\left(0+\frac{1}{8}+2+\frac{81}{8}+16\right)[/tex] = 7.0625 - this is our solution. The correct answer is option c, and i hope this clarifies why.
BrO3- (aq) + NO2(aq) → Br-(aq) + NO3-(aq) Balance this reaction in acidic conditions?
Answer:
BrO₃⁻ (aq) + NO₂(aq) + 4 H⁺→ Br⁻(aq) + NO₃⁻ + 2 H₂O
Explanation:
The law of conservation of matter states that since no atom can be created or destroyed in a chemical reaction, the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products.
Then, you must balance the chemical equation. For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts.
The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.
By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.
Then, taking into account all of the above, you can determine the amount of elements on each side of the equation:
Left side: 1 Br, 5 O and 1 N
Right side: 1 Br, 3 O and 1 N
If the reaction occurs in an acidic medium:
Each excess oxygen atom is balanced by adding a molecule of water to the other side of the reaction. Hydrogens are balanced by adding protons (H⁺) on the opposite side to the water molecules.So, balancing the oxygen:
BrO₃⁻ (aq) + NO₂(aq) → Br⁻(aq) + NO₃⁻ + 2 H₂O
Left side: 1 Br, 5 O and 1 N
Right side: 1 Br, 5 O, 1 N and 4 H
Then, balancing the hydrogens:
BrO₃⁻ (aq) + NO₂(aq) + 4 H⁺→ Br⁻(aq) + NO₃⁻ + 2 H₂O
Left side: 1 Br, 5 O, 1 N and 4 H
Right side: 1 Br, 5 O, 1 N and 4 H
You can see that you have the same amount on each side of the reaction. So the reaction is balanced.
Question 8 of 50
2 Points
Which type of structure would contain a few non-metal atoms?
O A. Giant covalent structure
B. Simple covalent structure
C. Metallic lattice
OD. Ionic lattice
Reset Selection
Answer:
b
Explanation:
b
The type of structure would contain a few non-metal atoms are simple covalent structure. Option B is correct.
What is covalent structure?A covalent bond is a chemical bond between two atoms, ions or molecules in which electron pairs are shared between elements and covalent bond can also be said as a molecular bond.
Covalent bonds form or made by between two non-metallic atoms or compounds with identical or same electronegativity for example hydrogen and oxygen are two non metals and bond to form water molecule.
Therefore, type of structure would contain a few non-metal atoms are simple covalent structure. Option B is correct.
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1. Consider the following equilibrium system: C(s) + CO2(g) 2CO(g)
∆Hr° = +120 kJ
Indicate the shift in equilibrium, if any, for each of the following scenarios: a) Adding CO2(g) b) Adding C c) Lowering the temperature d) Increasing pressure e) Adding a catalyst
Answer:
a) equilibrium shifts towards the right
b) equilibrium shifts towards the right
c) equilibrium shifts towards the left
d) has no effect on equilibrium position
e) has no effect on equilibrium position
Explanation:
A reversible reaction may attain equilibrium in a closed system. A chemical system is said to be in a state of dynamic equilibrium when the rate of forward reaction is equal to the rate of reaction.
According to Le Chateliers principle, when a constraint such as a change in temperature, pressure, volume or concentration is imposed upon a system in equilibrium, the equilibrium position shifts in such a way as to annul the constraint.
When the concentration of reactants is increased, the equilibrium position is shifted towards the right hand side and more products are formed. For an endothermic reaction, the reverse reaction is favoured by a decrease in temperature. Increase in pressure has no effect on the system since there are equal volumes on both sides of the reaction equation. Similarly, the addition of a catalyst has no effect on the equilibrium position since it speeds up both the forward and reverse reactions to the same extent.
Calculate the number of g of KCN that will react with 1.06 mol of HCl.
Answer:
68.9 g of KCN.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
KCN + HCl → KCl + HCN
From the balanced equation above,
1 mole of KCN reacted with 1 mole of HCl.
Next, determination of the number of mole of KCN needed to react with 1.06 moles HCl.
This is illustrated below:
From the balanced equation above,
1 mole of KCN reacted with 1 mole of HCl.
Therefore, 1.06 moles of KCN will also react with 1.06 moles of HCl.
Finally, we shall convert 1.06 moles of KCN to grams.
This can be obtained as follow:
Molar mass of KCN = 39 + 12 + 14 = 65 g/mol.
Mole of KCN = 1.06 moles
Mass of KCN =...?
Mole = mass /Molar mass
1.06 = mass of KCN / 65
Cross multiply
Mass of KCN = 1.06 x 65
Mass of KCN = 68.9 g
Therefore, 68.9 g of KCN is needed to react with 1.06 moles of HCl.
Three compounds that nitrogen and oxygen can form are NO, NO2, and N2O3. The law of multiple proportions tells you
A. the ratio of nitrogen to oxygen is always the same.
B. nitrogen combines with oxygen in small whole number mass ratios.
C. energy is conserved.
D. mass is conserved
The postulation of the law of multiple proportions tells us that; Choice B. nitrogen combines with oxygen in small whole number mass ratios.
The law of Multiple Proportions
Law of multiple proportions states that if two elements form more than one compound, then the ratios of the masses of the second element which combine with a fixed mass of the first element will always be ratios of small whole numbers.
On this note, nitrogen combines with oxygen in small whole number mass ratios.
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The table below gives the numbers of protons, electrons, and neutrons in four atoms.
Atom
11
2
Number of protons
39
40
|39
40
Number of electrons
39
40
39
40
Number of neutrons
52
50
154
51
3
14
Based on the information that is given, which atom in the table has the highest mass?
O 1
2
3
Answer:
The atom with the highest mass with 139 protons and 154 neutrons, is atom 3
Explanation:
The information given are;
The number of protons, p, the number of electrons, e, and the number of neutrons, n, we have;
p, e, n,
39, 39, 52
40, 40 50
139, 39 154
40, 39 51
Based on the information that the mass of the proton = 1.67262 × 10⁻²⁷ kg
The mass of the electron = 1.094 × 10⁻³¹ kg
the mass of the neutron = 1.674927471 × 10⁻²⁷ kg
We have that the atom with the most number of neutron and proton which is atom 3, has the highest mass
we have
What is the pH of a solution that has [OH-] = 4.0 x 10-'M?
Answer: 13.60
Explanation:
[tex]\frac{10^{-14} }{4.0 x 10^{-} }[/tex] = 2.5 x10^-14 this =[tex][H_{3} O^{+} ][/tex]
pH = -log[tex][H_{3}O^{+} ][/tex]
pH= -log( 2.5 x10^-14) = 13.60
Calculations
Weight of acetanilide = 2.7g
Theoretical yield of Nitroaniline =
Weight of para-nitroaniline = 1.5g
Percentage yield of para-nitroaniline =
Please help me which this and show me how you get the answer thank you
Answer:
Theoretical yield: 2.75g of paranitroaniline
Percentage yield: 54.5%
Explanation:
In strong-acid medium, acetanilide (Molar mass: 135.16g/mol) reacts producing para-nitroaniline (138.12g/mol) in a 1/1 reaction.
Theoretical yield of para-nitroaniline is the mass produced assuming a yield of 100%. That is:
2.7g acetanilide × (1mol / 135.16g) = 0.020 moles of acetanilide.
Assuming a yield of 100% are 0.020 moles of paranitroaniline. Theoretical yield is:
0.020 moles × (138.12g / mol) =
Theoretical yield: 2.75g of paranitroanilinePercentage yield is:
(Actual yield / theoretical yield) × 100
Actual yield was 1.5g and percentage yield will be:
Percentage yield: (1.5g / 2.75g) × 100
Percentage yield: 54.5%A certain polyatomic ion contains 49 protons and 50 electrons. What's the net charge of this ion?
A. +1
B.-2
C. +2
D. -1
Answer:
The charge - 1
Because the charge of proton is + and electron -
Charge = +49 +(-50)
= - 1
Explanation:
Help PLZ!!! Which statement accurately represents the arrangement of electrons in Bohr’s atomic model? -Electrons move around the nucleus in fixed orbits of equal levels of energy. -Electrons move around the nucleus in fixed orbits of increasing levels of energy. -Electrons move randomly in the relatively large space surrounding the nucleus. -Electrons vibrate in fixed locations around the nucleus.
Answer:
electrons move around the nucleus in fixed orbits of equal amounts of energy
Explanation:
To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. The correct option is option B.
What is atom?Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.
In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron.
According to Bohr’s atomic model, electrons move around the nucleus in fixed orbits of increasing levels of energy.
Therefore, the correct option is option B that is electrons move around the nucleus in fixed orbits of increasing levels of energy.
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Which of the following is NOT a reason atom economy is important?
A. Minimize waste of non-renewable reactants
B. To reduce the amount of water used in cooling reactions
C. Make as much product as possible
D. Increase energy use during reactions
Reset Selection
Answer:
Increase energy use during reactions
Explanation:
Answer via Educere/ Founder's Education
Increase energy use during reactions. Hence, option D is correct.
What is an atom?An atom is any particle of matter at its most basic level which contains at least one proton.
A reaction with a high atom economy is important in industry because it uses lesser natural resources, produces less waste, and is better for the environment. It is also cheaper to produce and more sustainable.
Increasing energy used during reactions is NOT a reason atom economy is important.
Hence, option D is correct.
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Consider the reaction below.
NH4 + H20 - NH3 + H30"
Which is an acid-conjugate base pair?
O NHA and NH3
O NH4" and H30*
O H20 and NH3
O H20 and H20"
Answer:
The correct ans is....
Option B) NH4" and H30*
Explanation:
NH4" and H30* is an example of conjugate pair
Hope this helps....
Pls mark my ans as brainliest :)PLS, PLS, PLSThe acid-conjugate base pair : ( B ) NH₄⁺ and H₃O⁻
The chemical reaction is
NH₄ + H₂O --> NH₃ + H₃O
Acid-conjugate base pairAn acid-conjugate base pair is a pair that consists of two substances that are different from each other just by the presence or absence of a proton ( H⁺ ) it helps to determine the relative strengths of acids and bases.
Hence we can conclude that the acid-conjugate base pair : ( B ) NH₄⁺ and H₃O⁻.
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When the equation below is balanced with the lowest possible whole number coefficients, what is the sum of the coefficients? Ca(s) + HCl(g) → CaCl2(s) + H2(g)
Answer:
ca(s)+hcj(g)cacI 2 (s)+H2(g)
Explanation:
The equation below is balanced with the lowest possible whole-number coefficients, the sum of the coefficients Ca(s) + HCl(g) → CaCl2(s) + H2(g) is
ca(s)+hcj(g)cacI 2 (s)+H2(g).
What is the sum of the coefficients when the equation for the combustion of ammonia is balanced using the smallest possible whole numbers?The sum of the coefficients is 2+3+4+3=12.
What type of reaction is Ca 2hcl → CaCl2 H2?Type of Chemical Reaction: For this reaction, we have a single displacement reaction. Balancing Strategies: In this reaction Calcium (Ca) metal is reacting with Hydrochloric acid (HCl). the Ca replaces the H in HCl and we end up with CaCl2 and H2.
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For the reaction C + 2H2 - CH2, how many moles of hydrogen are required to produce
19.26 mol of methane, CHA?
Select one:
O a. 19.26
O b. 38.52
O c. 15.0
O d. 24.7
Answer: 38.52 moles of hydrogen will be required to produce 19.26 mol of methane
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} CH_4=19.26moles[/tex]
The balanced chemical reaction is:
[tex]C+2H_2\rightarrow CH_4[/tex]
According to stoichiometry :
1 mole of [tex]CH_4[/tex] is produced by = 2 moles of [tex]H_2[/tex]
Thus 19.26 moles of [tex]CH_4[/tex] will be produced by =[tex]\frac{2}{1}\times 19.26=38.52moles[/tex] of [tex]H_2[/tex]
Thus 38.52 moles of hydrogen will be required to produce 19.26 mol of methane
the reaxtion between calcium and nitrogen to form calcium nitride is a redox reaction.
In terms of electrons, explain why calcium is the reducing agent.
Determine which reaction has the highest activation energy
Answer:
we need to look at what actually happens to reactant molecules during a chemical. in order for the reaction to take place , some or all of the chemical bonds in the reactants must be broken so that the new bonds, those of the products , can form.
Answer:
Graph 3
Explanation:
got it right.
If an atom of rubidium (Rb) were to ionize, it would ______ ______ electron(s).
Pretty sure it would lose electrons.
If an atom of rubidium (R b) were to ionize, it would loose electron(s).
What do you mean by ionization of atom ?Ionization is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons,.
Ionization is when a neutral atom or molecule can be converted into electrically charged atoms by gaining or losing a free electron.
Ionization happens during the process of a chemical reaction. To ionize an atom or a molecule, either loses or gains electrons―the electron which is either gained or lost forms an ion.
Therefore ,if an atom of rubidium (R b) were to ionize, it would loose electron(s).
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A solution of Cuso, is labelled 1.743 M. How much Cuso, in grams, must be used to make
1.4957 liter of solution?
Select one:
O a. 416.1
Ob. 0.007301
O c. 166.6
Od. 129.2
Answer:
Option A. 416.1 g.
Explanation:
Data obtained from the question include the following:
Molarity = 1.743 M
Volume = 1.4957 L
Mass of CuSO4 =..?
Next, we shall determine mole of CuSO4 present in the solution.
This is illustrated below:
Molarity is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the mole CuSO4 present in the solution as follow:
Molarity = 1.743 M
Volume = 1.4957 L
Mole of CuSO4 =..?
Molarity = mole /Volume
1.743 = mole of CuSO4 /1.4957
Cross multiply
Mole of CuSO4 = 1.743 x 1.4957
Mole of CuSO4 = 2.607 moles
Finally, we shall convert 2.607 moles of CuSO4 to grams.
This can be obtained as follow:
Molar mass of CuSO4 = 63.55 + 32.06 + (16x4) = 159.61 g/m
Mole of CuSO4 = 2.607 moles
Mass of CuSO4 =..?
Mole = mass /molar mass
2.607 = mass of CuSO4 /159.61
Cross multiply
Mass of CuSO4 = 2.607 x 159.61
Mass of CuSO4 = 416.1 g
Therefore, 416.1 g of CuSO4 is needed to prepare the solution.
Calculate the number of moles of BaF2 in a 10.0 g sample of BaF2.
Answer:
The number of moles = 0.06 moles
Explanation:
i) Formula
Number of moles = Mass of the sample ÷ Molar masses of the substances
ii) Number of moles = 10.0 ÷ (137)+(19×2)
= 10.0 ÷ 175
= 0.06 moles
Answer:
0.06moles
Explanation:
I did this question already and I got it right.
Which of the following shows how rate depends on concentrations of reactants?
Answer:
C
Explanation:
Rate = k(A)m(B)n
The correct option is C.
What are K , m and N in the rate law equation?
The specific rate constant (k) is the proportionality constant relating the rate of the reaction to the concentrations of reactants.The exponents m and n are the reaction orders and are typically positive integers, though they can be fractions, negative, or zero.
What do you mean by concentrations of reactants?
The increase in the concentration of reactants, the rate of reaction increases. Ions and molecules interact to form a new compound on increasing the concentration.
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37.2 liters of a gas has a pressure of 362.43 kPa at 46.5 °C. If the pressure increases to
693.9 kPa and the temperature to 149.2°C, what would be the new volume of the gas?
Select one:
O a. 25.7
O b. 62.3
O c. 54
O d. 25.672
Answer:25.7
Explanation:
The temperature of a sample of gas at 8.5 atm and 59.2 °C increases to 140.0 °C. If the
volume is unchanged, what is the new gas pressure?
Select one:
O a. 10.6
Ob. 20.1
Oc. 6.84
Od. 119
Answer:
since that's the closest option we have
10.6atm
Explanation:
Since volume is constant
P1/T1 = P2/T1
P1 =8.5atm
T1 = 59.2°C = 332.2k
T2 = 140°C = 413k
P2 = ?
8.5/332.2 = P2/413
0.026 = P2/413
P2 = 0.026 x 413
P2 = 10.74atm
Read the two passages. Silicon is an element that is directly below carbon on the periodic table. Silicon can form bonds similar to carbon. Silicon-silicon single bonds require 222 kJ/mol of energy to break. Based on the statements, how much energy would it take to break a carbon-carbon single bond?
Answer:
100kj/mol
Explanation:
Calculate the amount of 0.1 M acid needed to neutralize 10,000 liters of pH 8.0 water. The acid is Sulfuric Acid - H2SO4 Show your work for brainliest
Answer:
0.963
Explanation:
pH is the potential of hydrogen that can be determined by the hydrogen or hydroxide ion concentration. 10 mL is the amount required of 0.1 M to neutralize.
What is pH?pH estimates the acidic and the basicity of the solution when a solute is dissolved in the solvent.
Sulfuric acid is dissociated as:
H₂SO₄(aq) ⇌ H⁺(aq) + HSO₄⁻(aq)
pH is calculated as:
pH = -log [H⁺]
[H⁺] = 1x10⁻⁸ M
The moles in 10,000 L is, 10000L × 1x10⁻⁸ = 0.0001 moles
Moles of sulfuric acid required:
0.0001 moles × ( 1 mol H2SO4 ÷ 1 mol H⁺) = 0.001 moles
Further, volume is calculated as:
0.001 × (1L ÷ 0.1moles) = 0.01 L
Therefore, 10 mL of 0.1 M acid is needed to neutralize.
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Which group in the periodic table contains the lightest ferromagnetic element?
A. Group 7
B. Group 8
C. Group 10
D. Group 9
Group 8 in the periodic table contains the lightest ferromagnetic element. Therefore, option B is correct.
What is ferromagnetic material?Ferromagnetism can be described as a property of certain materials that results in a large observed magnetic permeability and large magnetic coercivity to form a permanent magnet.
Ferromagnetic materials are metals attracted to a magnet, a consequence of large magnetic permeability. Magnetic permeability can be defined as the induced magnetization of a material because of the presence of an external magnetic field.
A steel plate can acquire a permanent magnetization, which depends not only on the strength of the applied field but varies greatly among ferromagnetic materials.
Ferromagnetism can be described as the strongest type and is responsible for the phenomenon of magnetism in magnets. Substances weakly to magnetic fields with 3 other types of magnetism which are paramagnetism, diamagnetism, and antiferromagnetism.
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