Answer:
323.15 or just 323 depending on the teacher
3 attempts left Be sure to answer all parts. Which indicators that would be suitable for each of the following titrations: (a) CH3NH2 with HBr thymol blue bromophenol blue methyl orange methyl red chlorophenol blue bromothymol blue cresol red phenolphthalein (b) HNO3 with NaOH thymol blue bromophenol blue methyl orange methyl red chlorophenol blue bromothymol blue cresol red phenolphthalein (c) HNO2 with KOH thymol blue bromophenol blue methyl orange methyl red chlorophenol blue bromothymol blue cresol red phenolphthalein
An indicator usually signals the endpoint of a neutralization reaction by undergoing a color change. They aid in discovering the point of equivalence of a titration.
The kind of indicator used depends on the nature of acid/base reacted.
In the case of CH3NH2 with HBr which strong acid and weak base titration, suitable indicators include; bromophenol blue, methyl orange, methyl red, and chlorophenol blue.
In the case of HNO3 with NaOH, this is a strong acid, strong base titration hence phenolphthalein, methyl red, chlorophenol, and bromothymol blue cresol red blue are suitable indicators.
In the case of HNO2 with KOH, this a weak acid, strong base titration and the suitable indicators are cresol red and phenolphthalein.
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The big bang theory suggests that the origin of the universe began with
that exploded and
expanded.
Answer:
Yes?
Explanation:
If you're asking whether or not that's true, then the Big Bang suggests a way the universe might have formed, so yes it's true
Answer:
A star
Explanation:
Which of the following chemical reactions is reversible?
A. The neutralization of an acid.
B. The burning of wood.
C. The freezing of water into ice
D. The dehydration of copper sulfate (CuSO4).
The freezing of water into ice and the dehydration of copper sulfate are both reversible. The correct options are C and D.
What are reversible reactions?They are reactions in which the reverse can occur.
The freezing of water into ice can be undone. That is, the ice can be thawed back to water.
The dehydration of copper sulfate involves the removal of water molecules. As soon as water becomes available again, the reaction is reversed.
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how do we use the circle of fifths
Explanation:
in the terms of interval,thats a major sixth up or a minor third using the circle of fifths simply move three position clock wise around the to find the relative minor! so starting from C,count one( G),two( D)and then three:A is related to minor key.
3. (07.05 LC)
When zinc reacts with hydrochloric acid, it produces hydrogen gas. As the reaction proceeds, why does the rate of production of hydrogen gas decrease? (3 points)
the rate would decrease because the reactants are being depleted.
Which of the following is used in EBRT?
O Silver tube
O Gold tube
O Copper tube
O Iron tube
Copper tube is used in EBRT.
What is meant by EBRT?External Beam Radiation. Therapy (EBRT) is a type of radiation therapy that directs a beam of radiation from outside the body, toward cancerous tissues inside the body.External beam radiation therapy (EBRT) is the most common type of radiation therapy. It directs high-energy radiation beams at the cancer.Copper tube is used in EBRT.
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Please help chemistry ASAP
Will give brainly
Answer:
B
Explanation:
A chemist dissolves 14.0 g of calcium hydroxide in one beaker of water, and 17.0 g of iron(III) chloride
in a second beaker of water. Everything dissolves.
When the two solutions are poured together, solid iron(III) hydroxide precipitates.
1. Write a balanced molecular equation.
2. Determine the identity of the limiting reactant.
3. Predict the mass of iron(III) hydroxide product.
Answer:
See detailed explanation.
Explanation:
Hello there!
In this case, for the given scenario, we will proceed as follows:
1. Here, we infer that the products are iron (III) hydroxide (precipitate) and calcium chloride:
[tex]3Ca(OH)_2+2FeCl_3\rightarrow 3CaCl_2+2Fe(OH)_3[/tex]
2. In this step we firstly calculate the moles of both reactants, by using their molar masses 74.093 and 162.2 g/mol respectively:
[tex]14.0gCa(OH)_2*\frac{1molCa(OH)_2}{74.093gCa(OH)_2}=0.189molCa(OH)_2 \\\\17.0gFeCl_3*\frac{1molFeCl_3}{162.2gFeCl_3}=0.105molFeCl_3[/tex]
Now, we calculate the moles of calcium hydroxide consumed by 0.105 moles of iron (III) chloride by using the 3:2 mole ratio between them:
[tex]0.105molFeCl_3*\frac{3molCa(OH)_2}{2molFeCl_3} =0.157molCa(OH)_2[/tex]
Thus, we infer that calcium hydroxide is in excess as 0.189 moles are available for it but just 0.157 moles react and therefore, iron (III) chloride is the limiting reactant.
3. Here, we use the moles of iron (III) chloride we've just computed, the 2:2 mole ratio with iron (III) hydroxide and its molar mass (106.867 g/mol) as shown below:
[tex]0.105molFeCl_3*\frac{2molFe(OH)_3}{2molFeCl_3} *\frac{106.867gFe(OH)_3}{1molFe(OH)_3} \\\\=11.2gFe(OH)_3[/tex]
Regards!
Question 9 of 10
Which statement correctly describes magnetic field lines?
O A. They cross each other at right angles.
B. They always point away from a south pole.
C. They show the direction a south pole will point.
D. They join north pole to south pole..
All of the following statements concerning real cases is correct EXCEPT Group of answer choices molecules of real gases are attracted to each other. molecules of real gases occupy no volume. nonideal gas behavior is described by the Van der Waals Equation. the pressure of a real gas is due to collisions with the container. the pressure of a real gas at low temperatures is lower than for ideal gases.
Answer:
molecules of real gases occupy no volume.
Explanation:
As all the real gases are composed of particles that occupy the non-zero volume that is the excluded volume. If the gas is behaving in an ideal manner. The correction becomes negatable and is relative to the total volume. The extended volume is volume that is taken by the non ideal gas particles.If the concentration of products is increased the equilibrium is shifted from * left to right/ to the left/ right to left /down left
Answer:
to the left
Explanation:
If the concentration of products is increased for a reaction that is in equilibrium, the equilibrium would shift to the left side of the reaction (the reactant's side).
For a reaction that is in equilibrium, the reaction is balanced between the reactants and the products. According to Le Cha telier's principle, if one of the constraints capable of influencing the rate of reactions is applied to such a reaction that is in equilibrium, the equilibrium would shift so as to neutralize the effects created by the constraint.
Hence, in this case, if the concentration of the products of a reaction in equilibrium is increased, the equilibrium would shift in such a way that more reactants are formed so as to annul the effects created by the increase in the concentration of the products. Since reactants are always on the left side of chemical equations, it thus means that the equilibrium would shift to the left.
Question 1 of 10
What is the correct orientation of the bar magnet, based on the magnetic field
lines shown?
A. North pole on the left end and south pole on the right end
B. South pole on the top edge and north pole on the bottom edge.
C. South pole on the left end and north pole on the right end
D. North pole on the top edge and south pole on the bottom edge
Answer:
d. north pole on the top edge and south pole on the bottom edge
Explanation:
During a reaction with solids generally the _______ the size of each piece, the larger the total surface area. This means _______ collisions and a greater chance of reaction.
A. smaller, more
B. larger, more
C. larger, less
D. smaller, less
Answer:
A
Explanation:
I'm assuming this question implies that the surface area is in relation to the volume of the pieces. In that case, the SMALLER the size of each piece, the larger the surface area. This is because more particles are able to fit into the container if they are smaller, leading to more surface area. Since more pieces can fit into the container, MORE collisions happen according to collision theory. I cannot add a link, but for a helpful analogy, look up "How To Speed Up Chemical Reactions (and get a date) - Aaron Sams.
Answer: A. smaller, more
Explanation: Founders Educere answer
Balance the following skeleton reaction and identify the oxidizing and reducing agents: Include the states of all reactants and products in your balanced equation. You do not need to include the states with the identities of the oxidizing and reducing agents.
NO_2(g) rightarrow NO_3^-(aq) +NO_2^- (aq) [basic]
The oxidizing agent is:______.
The reducing agent is:_______.
Answer:
a. 2NO₂ (g) + 2OH⁻ (aq) → NO₃⁻ (aq) + NO₂⁻ (aq) + H₂O (l)
b. i. NO₂⁻ is the oxidizing agent
ii. NO₃⁻ is the reducing agent.
Explanation:
a. Balance the following skeleton reaction
The reaction is
NO₂ (g) → NO₃⁻ (aq) + NO₂⁻ (aq)
The half reactions are
NO₂ (g) → NO₃⁻ (aq) (1) and
NO₂ (g) → NO₂⁻ (aq) (2)
We balance the number of oxygen atoms in equation(1) by adding one H₂O molecule to the left side.
So, NO₂ (g) + H₂O (l) → NO₃⁻ (aq)
We now add two hydrogen ions 2H⁺ on the right hand side to balance the number of hydrogen atoms
NO₂ (g) + H₂O (l) → NO₃⁻ (aq) + 2H⁺ (aq)
The charge on the left hand side is zero while the total charge on the right hand side is -1 + 2 = +1. To balance the charge on both sides, we add one electron to the right hand side.
So, NO₂ (g) + H₂O (l) → NO₃⁻ (aq) + 2H⁺ (aq) + e⁻ (4)
Since the number of atoms in equation two are balanced, we balance the charge since the charge on the left hand side is zero and that on the right hand side is -1. So, we add one electron to the left hand side.
So, NO₂ (g) + e⁻ → NO₂⁻ (aq) (5)
We now add equation (4) and (5)
So, NO₂ (g) + H₂O (l) → NO₃⁻ (aq) + 2H⁺ (aq) + e⁻ (4)
+ NO₂ (g) + e⁻ → NO₂⁻ (aq) (5)
2NO₂ (g) + H₂O (l) + e⁻ → NO₃⁻ (aq) + NO₂⁻ (aq) + 2H⁺ (aq) + e⁻ (4)
2NO₂ (g) + H₂O (l) → NO₃⁻ (aq) + NO₂⁻ (aq) + 2H⁺ (aq)
We now add two hydroxide ions to both sides of the equation.
So, 2NO₂ (g) + H₂O (l) + 2OH⁻ (aq) → NO₃⁻ (aq) + NO₂⁻ (aq) + 2H⁺ (aq) + 2OH⁻ (aq)
The hydrogen ion and the hydroxide ion become a water molecule
2NO₂ (g) + H₂O (l) + 2OH⁻ (aq) → NO₃⁻ (aq) + NO₂⁻ (aq) + 2H₂O (l)
2NO₂ (g) + 2OH⁻ (aq) → NO₃⁻ (aq) + NO₂⁻ (aq) + H₂O (l)
So, the required reaction is
2NO₂ (g) + 2OH⁻ (aq) → NO₃⁻ (aq) + NO₂⁻ (aq) + H₂O (l)
b. Identify the oxidizing agent and reducing agent
Since the oxidation number of oxygen in NO₂ is -2. Since the oxidation number of NO₂ is zero, we let x be the oxidation number of N.
So, x + 2 × (oxidation number of oxygen) = 0
x + 2(-2) = 0
x - 4 = 0
x = 4
Since the oxidation number of oxygen in NO₂⁻ is -1. Since the oxidation number of NO₂⁻ is -1, we let x be the oxidation number of N.
So, x + 2 × (oxidation number of oxygen) = 0
x + 2(-2) = -1
x - 4 = -1
x = 4 - 1
x = 3
Also, the oxidation number of oxygen in NO₃⁻ is -1. Since the oxidation number of NO₃⁻ is -1, we let x be the oxidation number of N.
So, x + 2 × (oxidation number of oxygen) = -1
x + 3(-2) = -1
x - 6 = -1
x = 6 - 1
x = 5
i. The oxidizing agent
The oxidation number of N changes from +4 in NO₂ to +3 in NO₂⁻. So, Nitrogen is reduced and thus NO₂⁻ is the oxidizing agent
ii. The reducing agent
The oxidation number of N changes from +4 in NO₂ to +5 in NO₃⁻. So, Nitrogen is oxidized and thus and NO₃⁻ is the reducing agent.
Ggggggggggggggggg666666666666666
1.
the process in which plants
and some other organisms use the energy in sunlight to
make food.
2.
a green pigment that traps
energy from the sun.
3. A
a stiff structure that surrounds
and protects a cell; found in plant, fungus, and some
bacteria cells.
4. A
found in the nucleus of
a cell, a long nucleic acid molecule containing the genetic
instructions for the development and functioning of all
living organisms.
5.
cells.
is living things consisting of many
Answer:
1) Photosynthesis
Photosysnthesis is the process in which plantsand some other organisms usethe energy in sunlight to make food.
2) Chloroplast
Chloroplast is a green pigment that traps energy from the sun.
3) Cell Wall
Cell wall is a stiff structure that surrounds and protects a cell; found in plant, fungus, and some bacteria cells.
4) DNA
DNA is found in the nucleus of a cell, a long nucleic acid molecule containingthe
genetic instructions for the development and functioning of all living organisms.
5) Cell Organeles
Cells is living things consisting of many cell organeles
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the water in a glass does not contain any other substance.what kind of water is it
Answer:
natural mineral water.
How many chromosomes do we not understand?
Answer:
we don't understand why humans have only 46 chromosomes
Answer:
46 chromosomes is what we don't understand
Given the balanced chemical equation for the decomposition for INO, and the rate of disappearance of INO, write the expressions for the rates of appearance of I2 and NO.
2INO(g) → I2(g) + 2NO(g)
Reactant: Product(I2): Product(NO):
-∆[INO]/2∆t = ??/??
Answer:
rate of disappearance of -0.5d[INO]/dt
rate of appearance of I2 = d[I2]/dt
rate of appearance of No = 0.5*d[NO]/dt
Explanation:
According to chemical equilibrium, d[I₂]/dt and d[NO]/dt is the expressions for the rates of appearance of I₂ and NO respectively.
What is chemical equilibrium?Chemical equilibrium is defined as the condition which arises during the course of a reversible chemical reaction with no net change in amount of reactants and products.A reversible chemical reaction is the one wherein the products as soon as they are formed react together to produce back the reactants.
At equilibrium, the two opposing reactions which take place take place at equal rates and there is no net change in amount of the substances which are involved in the chemical reaction.At equilibrium, the reaction is considered to be complete . Conditions which are required for equilibrium are given by quantitative formulation.
Factors which affect chemical equilibrium are change in concentration , change in pressure and temperature and presence of catalyst.
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a leaking tap drops water at the rate of 3 drops every second.each drop is approximately 1 ml. how many liters of water will leak from the tap during a day?
a. 5 liters
b. 50 liters
c.500 liters
d.15 liters
A leaking tap that drops water at the rate of 3 drops every second, will leak 259.2 L in a day.
We know that a leaking tap drops water at the rate of 3 drops every second and that each drop is approximately 1 ml. The milliliters of water dropped every second are:
[tex]\frac{3drop}{1s} \times \frac{1mL}{1drop} = \frac{3mL}{1s}[/tex]
We want to know the number of seconds in 1 day. We will use the following conversion factors:
1 day = 24 h1 h = 60 min1 min = 60 s[tex]1day \times \frac{24h}{1day} \times \frac{60min}{1h} \times \frac{60s}{1min} = 86400 s[/tex]
3 mL of water are dropped every second. The mL of water dropped in 86400 s are:
[tex]86400 s \times \frac{3mL}{1s} = 259200 mL[/tex]
Finally, we will convert mL to L using the conversion factor 1 L = 1000 mL.
[tex]259200 mL \times \frac{1L}{1000 mL} = 259.2 L[/tex]
Approximately 259.2 L of water will be dropped in 1 day.
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What do you predict the chemical formula for the compound formed between calcium and sulfur?
Answer:
calcium donates two vanence electrons to sulfur atom to form Ca2+ ion and an S2+ - ion
Carbonic acid (H₂CO₃) is a polyprotic acid. When carbonic acid dissolves in water, which is higher, the concentration of HCO₃- ions or the concentration of CO₃²- ions?
Please explain!
The concentration of CO₃²⁻ ions will be higher
To explain, I want you to imagine H₂CO₃ in water.
we know that it will lose 2 of it's protons, and form 2 ions
The ion which is more stable will have a higher concentration because that ion will refuse to react with anything else, so once something turns into that specific ion, it's not going back... unless there's a more stabler ion possible
In this case, the 2 ions formed are: HCO₃⁻ and CO₃⁽²⁻⁾, drawing the structures of both the ions tells us that both of them have resonance, but the CO₃⁽²⁻⁾ ion has more resonance structures and hence is more stable
World leaders met in Copenhagen, Denmark in December 2009, to try to come up with an agreement that
would lead to reducing greenhouse gas emissions. They agreed that we need to reduce carbon dioxide
emissions 80% by the year 2050. How does Lester Brown feel about that?
Select one:
O a. He thinks it is a great achievement.
b. He thinks it is not fast enough
O c. He thinks that we do not need international cooperation
d. He thinks that greenhouse gas emissions are not the most important factor.
Clear my choice
Lester Brown thinks reducing carbon dioxide emissions 80% by 2050 is not fast enough.
Lester Brown is an American environmentalist who has focused on studying the environment and its protection. In recent years, he has made alerts for world leaders and large industries to strive to stop CO2 emissions because this greenhouse gas has a massive influence on global warming.
Therefore, Lester Brown considers that the projections of reduction of greenhouse gases (especially CO2) made by the world powers for the year 2050, ignore the reality because he considers that CO2 emissions must decrease by at least one 80% in 2020 to avoid drastic consequences in current living conditions. Therefore, the answer is B.
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Name the following alkane molecule:
CH3
CH3CCH3
CH3
A. 2-ethylpropane
B. 2-dimethylpropane
C. 2,2-dimethylpropane
not 100% sure but I think its C
The correct name for the given alkane molecule is 2,2-dimethylpropane. (Option C)
The given alkane molecule is composed of three carbon atoms. The central carbon atom is bonded to two methyl groups (CH₃) on either side. This results in a branched structure where the methyl groups are attached to the same carbon atom.
According to the rules of IUPAC nomenclature, the prefix "2,2-" indicates that the methyl groups are attached to the second carbon atom in the main chain. The parent chain, which consists of three carbon atoms, is named propane. Since there are two identical methyl groups attached to the second carbon atom, the compound is named 2,2-dimethylpropane.
Hence, the name of the given alkane molecule is 2,2-dimethylpropane.
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You find a clean 100-ml beaker, label it "#1", and place it on a tared electronic balance. You add small amount of unknown solid and place the
beaker with its contents on the balance. The recorded data is:
mass of the empty, clean beaker #1: 74.605 g
mass of the beaker #1 with the white solid: 74.896 g
Using the Law of Conservation of Mass, what is the mass of the unknown solid you placed in beaker #1?
Answer:
the mas is .291 g
Explanation:
the mass of a object does not change. so when added the substance the beaker. you had the mass of both objects together. you know the mass of the beaker and you know the mass of both. since mass does not change. the beakers mass is still 74.605g. the mass of both objects is 74.896. all you have to do is subtract the mass of the beaker from the total mass. 74.896 - 74.605 equals .291g. so the mass of the unknown substance Is .291g
Nitric acid and nitrogen monoxide react to form nitrogen dioxide and water, like this: At a certain temperature, a chemist finds that a 7.7 L reaction vessel containing a mixture of nitric acid, nitrogen monoxide, nitrogen dioxide, and water at equilibrium has the following composition: compound amount
HNO 16.2 g 11.0 g 18.6 g H20 236.7 g 3 NO NO
Calculate the value of the equilibrium constant K for this reaction. Round your answer to 2 significant digits.
Answer:
K = 3.3
Explanation:
Nitric acid, HNO3, reacts with nitrogen monoxide, NO, to produce nitrogen dioxide, NO2 and water H2O as follows:
2HNO3(g) + NO(g) → 3NO2(g) + H2O(g)
Where equilibrium constant, K, is:
K = [NO2]³[H2O] / [HNO3]²[NO]
[] is the molar concentration of each species at equilibrium.
To solve this question we need to find molarity of each gas and replace these in the equation as follows:
[NO2] -Molar mass NO2-46.0g/mol-
18.6g * (1mol/46.0g) = 0.404mol / 7.7L = 0.0525M
[H2O] -Molar mass:18.01g/mol-
236.7g * (1mol/18.01g) = 13.14 moles / 7.7L = 1.707M
[HNO3] -Molar mass:53.01g/mol-
16.2g * (1mol/53.01g) = 0.3056 moles / 7.7L = 0.0397M
[NO] -Molar mass: 30.0g/mol-
11.0g * (1mol/30.0g) = 0.367 moles / 7.7L = 0.0476M
Replacing:
K = [NO2]³[H2O] / [HNO3]²[NO]
K = [0.0525M]³[1.707M] / [0.0397M]²[0.0476M]
K = 3.3
Hey. what is the difference between a boulder and a rock? ]
And bonus: what did the duck say when she bought lipstick?
Answer:
The difference between a rock and a boulder can be explained in terms of size and detachment. A rock is defined by geologists as an aggregate of minerals. A boulder is a type of rock, specifically a large detached one. All boulders are rocks, but not all rocks are boulders.
A alkaloid compound contains 74.02% C, 8.710% H and 17.27% N. The empirical formula of the compound is___.
If 40.57 grams of it contains 0.2500 moles, then it's molecular formula will be:______.
C₁₀H₁₄N₂ is the empirical formula of the compound whose mass is 40.57 present in 0.2500 moles.
What are alkaloid compounds?Alkaloid compounds are those naturally present organic compounds in which nitrogen is present.
First we calculate the molecular mass of wanted compound by using the below formula:
n = W/M, where
n = no. of moles = 0.2500 moles (given)
W = given mass = 40.57 grams (given)
M = molar mass = 40.57 grams/= 0.2500 moles = 162.28 g/mole
In the question, given that:
% composition of carbon = 74.02%
% composition of hydrogen = 8.710%
% composition of nitrogen = 17.27%
Now we calculate the mass of these composition by using the below formula:
Composition mass = compound mass * % composition / 100
Mass of carbon = 162.28 * 74.02 / 100 = 120.11g
Mass of hydrogen = 162.28 * 8.710 / 100 = 14.13g
Mass of nitrogen = 162.28 * 17.27 / 100 = 28.02g
Now we calculate the moles of these composition to made empirical formula as:
Moles of carbon = 120.11 / 12 = 10
Moles of hydrogen = 14.13 / 1 = 14
Moles of nitrogen = 28.02 / 14 = 2
Thus, the empirical formula of the compound is C₁₀H₁₄N₂.
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In the reaction A + B + C + D, what are the reactants?
O A. Just B
B. Cand D
O c. A and B
O D. A and C
Answer:
C.
Explanation:
I believe that it should be A and B.
What mass of oxygen is needed for the complete combustion of 1.60-10^-3
g
of methane?
Express your answer with the appropriate units.
Answer:
6.4×10¯³ g of O₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
CH₄ + 2O₂ —> CO₂ + 2H₂O
Next, we shall determine the masses of CH₄ and O₂ that reacted from the balanced equation. This can be obtained as follow:
Molar mass of CH₄ = 12 + (4×1)
= 12 + 4
= 16 g/mol
Mass of CH₄ from the balanced equation = 1 × 16 = 16 g
Molar mass of O₂ = 2 × 16 = 32 g/mol
Mass of O₂ from the balanced equation = 2 × 32 = 64 g
SUMMARY:
From the balanced equation above,
16 g of CH₄ reacted with 64 g of O₂.
Finally, we shall determine the mass of O₂ needed to react with 1.6×10¯³ g of CH₄. This can be obtained as illustrated below:
From the balanced equation above,
16 g of CH₄ reacted with 64 g of O₂.
Therefore, 1.6×10¯³ g of CH₄ will react with = (1.6×10¯³ × 64) / 16 = 6.4×10¯³ g of O₂
Thus, 6.4×10¯³ g of O₂ is needed for the reaction.
