Answer:
They must be selected for a narrow pH range.
Explanation:
Indicators are compounds that change to a specific colour in a solution within a specific pH range.
The chemical indicators does not give the exact value of pH. They only provide the range of pH. They must be selected for a narrow pH range. The correct option is C.
What is chemical indicator?The acid base indicators or neutralization indicators are substances which are employed for the visual detection of the end point on the basis of their ability to change colour during the pH change that occurs in vicinity of the end point.
The chemical indicators are usually weak organic acids or bases which change colour in characteristic pH ranges. The particular range or interval of pH in which an acid-base indicator changes its colour is known as the colour-change interval.
Methyl orange is a weak base which changes its colour in the pH range 3.1-4.4 being red below pH 3.1 and yellow above pH 4.4.
Thus the correct option is C.
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Does a reaction occur when aqueous solutions of sodium sulfide and manganese(II) chloride are combined?
Oyes Ono
If a reaction does occur, write the net ionic equation.
Answer:
Yes, a reaction occurs
Explanation:
net ionic equation
Mn 2+ (aq) + S 2- (aq) --> MnS (s)
heeeeeeeeeeeeeeeeeeeeeeeeeeeeeelp
Explain the electrolysis of acidified water
Answer:
yqaeh
Explanation:
Electrolysis of acidified water
Water is a poor conductor of electricity, but it does contain some hydrogen ions , H +, and hydroxide ions, OH -. These ions are formed when a small proportion of water molecules naturally dissociate . ... H + ions are attracted to the cathode , gain electrons and form hydrogen gas.
How many grams of water should be added to 4.00 g NaOH to create 2.00% by mass NaOH solution?
Answer:
196 grams
because ^^^ was wrong and person in comments said it was 196 and it was right
When NaOH of 4.00 g is being added with water, the mass of water required to create 2.00% of NaOH solution by mass is 196 g.
What is mass percent of solute?It means that the particular amount of solute in terms of percentage is present in the solute.
Given the mass of the solute, NaOH is 4.00g
Suppose the mass of water required to add is x in g.
The mass percent of the solute is
[tex]\dfrac{2}{100} =\dfrac{4.00}{4.00 +x }[/tex]
x =196 g
Therefore, mass of water required to create 2.00% of NaOH solution by mass is 196 g.
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Chemical equation=CH4 + O2 = CO2 + H2O.
i. identify the products of the chemical reaction.
ii. explain why these are the products based on trends in the periodic table (the number of
valence electrons, electronegativity, etc.).
iii. identify the types of bonds in the reactants and products.
iv. identify the number of each type of bond in the reactants and products.
v. identify the type of reaction
Answer:
1.The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction.The combustion of methane or octane is exothermic; it releases energy. CH4 + 2 O2 → CO2 + 2 H2O + energy The energies of the products are lower than the energiies of the reactants.
Explanation:
how minimising the use of cars can help save the ozone layer
Answer:
minimizing the use of cars can help save the ozone layer by Minimizing the amount of gasoline which damages the ozone layer.
therefore the ozone layer is preserved.
have a nice day.
I need help with this question
Answer:
there is no question posted
Excessive use of chemical fertilizer cause chemical pollution.How?
Explanation:
Chemical fertilizers raise crop yields, but their heavy usage has hardened the soil, diminished fertility, reinforced pesticides, contaminated air and water, and emitted greenhouse gases, posing health and environmental risks.
Convert 75k to oC
(I’ll mark you as brainlister)
Answer:
-198.15 degrees Celsius
Explanation:
To convert to Celsius from Kelvin, subtract 273.15 from your temperature in Kelvin.
75K - 273.14 = 198 degrees C
carbon-dating was performed on an artefact that was found to have 25% of the original carbon-14 remaining in it
4A1 + 302 →
2Al2O3. How many grams of oxygen (O2)
are needed to produce 95 grams of
aluminum oxide (Al2O3)?
Answer: 44.706g Al2O3
Explanation:
4A1 + 302 → 2Al2O3
3×(16×2) 2{(27×2)+(16×3)}
= 96 = 204
So
To produce 204g of Al2O3,We need . 96g of O2
To produce 1g of Al2O3,We need
. (96÷204)= 0.47g of O2
To produce 95g of Al2O3,We need
. (0.47×95)= 44.706g of O2
.
So, 44.706 grams of oxygen (O2)
are needed to produce 95 grams of
aluminum oxide (Al2O3).
How does moving water help shape earth?
Answer:
Moving water helps plant's and islands form and grow. Which shapes earth.
Oo help it’s for a grade
Answer: D.kinectic energy
Explanation
Can someone help please
Answer:
fuse
Explanation:
fuses are made by metal alloys , have low melting point
How do I do nunber 8?
Answer:
DONT CLICK THAT LINK THAT IS HACK AND VIRUS
Explanation:
How many grams of sodium metal must be introduced to water to produce 3.3 grams of hydrogen gas?
Answer:
The mass of sodium metal that must be introduced to water to produce 3.3 grams of hydrogen gas, H₂, is approximately 18.82 grams of sodium metal
Explanation:
The given mass of hydrogen gas produced = 3.3 grams
The molar mass of hydrogen gas, H₂ = 2.016 g/mol
The number of moles of hydrogen gas in 3.3 grams of H₂, 'n', is given as follows;
n = Mass/(Molar mass)
n = 3.3 g/(2.016 g/mol) = 1.63690476 moles of H₂
The reaction of sodium and water can be written as follows;
2Na + 2H₂O → 2NaOH + H₂ (g)
2 moles of sodium produces 1 mole of hydrogen gas, H₂
Therefore;
1.63690476/2 moles of sodium will produce 1.63690476 moles of hydrogen gas, H₂
The molar mass of sodium, Na ≈ 22.989 g/mol
The mass of 1.63690476/2 moles of sodium, 'm', is given as follows;
m = 1.63690476/2 moles × 22.989 g/mol ≈ 18.8154018 grams ≈ 18.82 grams
The mass of sodium that will produce 3.3 grams of hydrogen, m ≈ 18.82 grams of sodium metal.
1. How many liters of a 0.50 M solution are needed to give 3.5 moles of solute?
Answer:
The volume of solution in liters required to make a 0.250 M solution from 3.52 moles of solute is 14.08 liters of solution
Explanation:
The question relates to the definition of the concentration of a solution which is the number of moles per liter (1 liter = 1 dm³) of solution
Therefore we have;
The concentration of the intended solution = 0.250 M
Therefore, the number of moles per liter of the required resolution = 0.250 moles
Therefore, the concentration of the required solution = 0.250 moles/liter
The volume in liters of the required solution that will have 3.52 moles of the solute is given as follows;
The required volume of solution = The number of moles of the solute/(The concentration of the solution)
∴ The required volume of solution = 3.52 moles/(0.250 moles/liter) = 14.08 liters
The required volume of solution to make a 0.250 M solution from 3.52 moles of solute = 14.08 liters.
Therefore the number of liters required to make a 0.250 M solution from 3.52 moles of solute = 14.08 liters.
CAN SOMEONE HELP ME WITH AS MANY AS POSSIBLE! I WILL GIVE MORE POINTS IF GIVEN ALOT
Answer:
1.Hydrogen peroxide,2.Potassium nitrate,3.Ethane,4.Ammonium phosphate,5.Aluminium sulfate,6.Barium hydroxide,7.Calcium phosphate,8.Calcium chloride,9.Copper nitrite,10.Iron oxide,11.Sulfuric acid,12.Phosphoric acid,13.Mercury chloride,14.Potassium sulfite,15.Potassium manganate,16.Magnesium acetate,17.Magnesium nitrate,18.Sodium chloride,19.Sodium acetate,20.Ammonium bromide
Organisms are classified into different kingdoms based on?...
Answer:
Food and cell type
Explanation:
Kingdoms are by far the most basic legal structure for living objects. Living objects are classified into realms depending on how they consume food, the kinds of cells that produce their bodies, and the total type of tissue in their bodies.
For which of the reactions listed below will Gibbs free energy always be.
positive?
O A. An exothermic reaction that decreases in entropy
B. An exothermic reaction that increases in entropy
O C. An endothermic reaction that decreases in entropy
D. An endothermic reaction that increases in entropy
I think the answer is: C. An endothermic reaction that decreases in entropy
An endothermic reaction that decreases in entropy. Hence, option C is correct.
What is entropy?Entropy is the energy of a system that is unuseful to do work.
For a reaction to be spontaneous, the Gibbs' Free Energy must be negative.
The equation for Gibbs Free energy is given by:
G= H-TS
Where, G = Gibbs free energy
H = Enthalpy of the reaction
T = Temperature of the system
S = Entropy of the system
Sign convention for all the quantities:
For H: It is negative for exothermic reactions and positive for endothermic reactions
For S: It is positive when there is an increase in entropy and it is negative when there is a decrease in entropy.
If we want G to be negative, the conditions necessary are:
G= (-ve) - (+ve) = -ve
The product of temperature and entropy must be positive and that will be positive when there is increase in entropy at any temperature.
Hence, option C is correct.
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When a substance freezes, _____.
it releases thermal energy
it absorbs thermal energy
it changes from a solid to a liquid
its temperature drops
Answer:
It's temperature drops, and if releases thermal energy
Answer:
Its temperature drops
What is the diameter of Neptune in standard notation and scientific notion?
Answer:
Standard notation: 49,244 km
Scientific notation: 4.92x10⁴ km
Explanation:
The diameter of Neptune in standard notation is:
49,244 km
In the standard notation, we write the result in a normal way.
Now, to express the diameter in scientific notation we need to use a base ten power as follows:
4.92x10⁴ km
In the above result, the positive exponent indicates that the number is larger. The decimal point is located near the first digit.
Therefore, the diameter of Neptune in standard notation is 49,244 km and in scientific notation is 4.92x10⁴ km.
I hope it helps you!
Which of the following would be a value measured using a scale in lab?
O Actual yield
O Percent yield
O Theoretical yield
O Molar ratio
Answer:
A. Actual Yield
Since all of the others are calculated not measured outright.
explain what is the difference between bohr and rutherford atomic models
Answer:
The Rutherford Model shows an atom with electrons orbiting a fixed, positively charged nucleus in set, predictable paths. The Bohr model shows electrons travel in defined circular orbits around the nucleus.
Which of the following is NOT a common property of water?
o Water has high surface tension.
o Water expands when it freezes.
o Ice is less dense than water.
o Water has low heat of vaporization.
Answer:
A = water has high surface tension
the answer is a hope this helps and plz give me brainlist :)
A(n)____ is a ripened ovary
If magnesium and nickel were used as electrodes to construct an electrochemical cell like the one shown at right, which metal would form the anode and which the cathode?
anode:
cathode:
Answer:
anode: magnesium
cathode: nickel
Explanation:
edg. 2021
En condiciones normales 1g de aire ocupa un volumen de 773 mL ¿ qué volumen ocupará la misma masa de aire a 0 ºC y la presión a 93,3 KPa *
Answer:
El volumen que ocupará la misma masa de aire es 839.49 mL.
Explanation:
Las condiciones normales de presión y temperatura (abreviado CNPT) o presión y temperatura normales (abreviado PTN o TPN), son términos que implican que la temperatura referenciada es de 0ºC (273,15 K) y la presión de 1 atm (definida como 101.325 Pa).
La ley de Boyle dice que “El volumen ocupado por una determinada masa gaseosa a temperatura constante, es inversamente proporcional a la presión” y se matemáticamente como
Presión*Volumen=constante
o P*V=k
La ley de Charles es una ley que dice que cuando la cantidad de gas y de presión se mantienen constantes, el cociente que existe entre el volumen y la temperatura siempre tendrán el mismo valor:
[tex]\frac{V}{T} =k[/tex]
La ley de Gay-Lussac establece que la presión de un volumen fijo de un gas, es directamente proporcional a su temperatura. Se expresa matemáticamente como:
[tex]\frac{P}{T} =k[/tex]
Combinando estas tres leyes se obtiene:
[tex]\frac{P*V}{T} =k[/tex]
Siendo un estado inicial 1 y un estado final 2, la expresión anterior queda determinada como:
[tex]\frac{P1*V1}{T1} =\frac{P2*V2}{T2}[/tex]
En este caso:
P1= 101325 PaV1= 773 mLT1= 273.15 KP2= 93,3 kPa= 93300 PaV2= ?T2= 0°C= 273.15 KReemplazando:
[tex]\frac{101325 Pa*773 mL}{273,15 K} =\frac{93300 Pa*V2}{273.15 K}[/tex]
y resolviendo obtenes:
[tex]V2=\frac{273.15 K}{93300 Pa} *\frac{101325 Pa*773 mL}{273,15 K}[/tex]
V2= 839,49 mL
El volumen que ocupará la misma masa de aire es 839.49 mL.
How many atoms in 12 moles of Mg?
Question 3
5 pts
The diagram shows a 21.7kg ball located on a shelf 1.6m above the ground. Which best describes the energy
of the ball?
o C. It has mechanical energy in the form of potential energy
O A. Its energy is lost once it falls off the shelf.
O B. Its energy depends upon the speed the ball will travel.
O D. It has mechanical energy in the form of kinetic energy.
Answer:
c
Explanation:
The ball of 21.7 kg which is located on a shelf 1.6 m above ground is having a mechanical energy in the form of potential energy. Hence, C best describes the energy of the ball.
What is potential energy ?Potential energy is the energy stored on it when the object is at rest. Kinetic energy of an object is generated by virtue of its motion. When a body starts moving its potential energy starts converts to kinetic energy.
The sum of kinetic and potential energy of an object is called its mechanical energy. An object has mechanical energy in the form of kinetic energy when it is at rest. When it starts to move its potential energy converts to kinetic energy.
Therefore, the ball of 21.7 kg placed in the shelf of height 1.6 m has a potential energy as long as it stays there on the shelf. Its potential energy = mgh
p = 21.7 kg × 9.8 m/s² × 1.6 m = 340.25 J
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