Observe the statements.
I. Phenolphthalein is a colourless solution
II. Phenolphthalein turns pink in basic solution
III. Phenolphthalein turns red in acidic solution
IV. Phenolphthalein remains colourless in acidic solution
Choose the correct option
a.I &II are correct
b.I & III are correct
c.I ,II & IV are correct
d.All the statements are correct

Answer:

Water can be used as the thermometric liquid. It expands and contracts with temperature so it can be used. It's just not a very good choice because: It's thermal expansion is not very large compared to other liquids like mercury.

Explanation:

Hope this help

The amount of the 240 g sample of the radioisotope that will remain after 525 billion years is 7.5 g

n = t / t½

n = 525 / 105

n = 5

N = N₀ / 2ⁿ

N = 240 / 2⁵

N = 240 / 32

N = 7.5 g

Learn more about half life:

https://brainly.com/question/26374513

#SPJ4

Answer:

7.5

Explanation:

edge

The number of moles of nickel(II) iodide (NiI2) present in a sample containing 7.18 moles of iodide ions is 3.59 moles.

To calculate the moles of nickel(II) iodide, we need to consider the stoichiometry of the compound. The formula of nickel(II) iodide is NiI2, indicating a 1:2 ratio of nickel to iodide ions. Therefore, for every 2 moles of iodide ions, we have 1 mole of nickel(II) iodide.
Given that the sample contains 7.18 moles of iodide ions, we can calculate the moles of nickel(II) iodide using the stoichiometric ratio. Moles of NiI2 = Moles of I- / 2. Plugging in the values, we find that Moles of NiI2 = 7.18 moles / 2 = 3.59 moles. Hence, there are 3.59 moles of nickel(II) iodide in the sample.

To know more about, stoichiometry, click here https://brainly.com/question/28780091

#SPJ11

Answer:

-8 m/s^2

Explanation:

The formula for acceleration is:

a= v^2 - v^1/t

a= acceleration

v^2- final velocity which in this case would be 0 since the jet comes to a stop.

v^1= original velocity which is 80 m/s.

t=time or 10s

Substitute the letters for the numbers and you get this:

a= 0 - 80/10

0 - 80= -80

-80 divided by 10 is -8.

Hope this helps! :)

The force occurs when the player kicks the ball is a contact force.

When the player kicks the ball, a force called a "contact force" occurs. This force is exerted by the player's foot on the ball, causing it to move forward.

b. Contact forces are forces that occur when two objects are in direct physical contact with each other. In this case, the player's foot is in contact with the ball, so the force exerted is a contact force.

c. As the ball soars through the air, a force called "gravitational force" is acting on the ball. This force is pulling the ball downwards towards the ground.

d. Gravitational force is a "non-contact force". It is a force that does not require physical contact between two objects to occur.

e. The force that brings the ball back down to the ground is also the gravitational force. As the ball rises into the air, it loses speed and momentum, and eventually the force of gravity overcomes the ball's upward motion, causing it to fall back down to the ground.

f. As mentioned earlier, the force that brings the ball back down to the ground is the gravitational force, which is a non-contact force.

Therefore, the force that brings the ball back down to the ground is also a non-contact force.

Learn more about force below.

https://brainly.com/question/12970081

#SPJ1

Answer:

 true.

Explanation:

Answer:

In a solution, the solute particles that are in the solvent are evenly mixed and so small that you can't see them. In a suspension, the pieces of solute are large and can be seen floating throughout the solvent. For example, dust floating through the air is a suspension.

Answer:

41.03 %

Explanation:

Given that,

The actual length of a strip of aluminum is 2.12 m

Observed length of a strip of aluminum is 1.25 m

We need to find the student's percent error. The percentage error on any value is given by :

\(\%=\dfrac{\text{observed-actual}}{\text{actual}}\times 100\)

Putting all values, we get :

\(\%=\dfrac{2.12-1.25}{2.12}\times 100\\\\\%=41.03\ \%\)

So, the percent error of the student is 41.03 %.

Answer:

22,600 J or 22.6 kJ

Explanation:

Assuming our planet to be a perfect sphere, then the average density of the Earth is approximately 5.514 g/cm^3.

The average density of the Earth can be calculated as follows:

The volume of a sphere can be calculated using the formula:

V = (4/3) * π * r^3

Where r is the radius of the sphere. The radius of the Earth is approximately 6,371 km.

The mass of the Earth is known to be approximately 5.97 x 10^24 kg.

So, the average density of the Earth can be calculated as follows:

density = mass / volume

density = 5.97 x 10^24 kg / [(4/3) * π * (6,371 x 10^3 m)^3]

density = 5.97 x 10^24 kg / (1.08 x 10^21 m^3)

density = 5514 kg/m^3

To convert from kilograms per cubic meter to grams per cubic centimeter, we multiply by 1000:

density = 5514 kg/m^3 * 1000 g/kg = 5.514 x 10^6 g/m^3 = 5.514 g/cm^3

So, the average density of the Earth is approximately 5.514 g/cm^3.

Learn more about the density of a planet here: https://brainly.com/question/29584807

#SPJ4

Answer:

A. Algae growth is high

Explanation:

Substances that contains high concentration of nitrates, phosphates etc add nutrients to the water body. This is because organisms like ALGAE consider these compounds nutrients needed for their growth and development. The process whereby these nutrients becomes excessive in a water body is referred to as EUTROPHICATION.

Eutrophication of a water body i.e excessive nutrients like nitrates in a water body like the North Carolina waters being described in this question will lead to rapid and excessive growth of algal species. This increase in algal growth can cause the water body to be low in oxygen content and ultimately become inhabitable by living organisms.

Answer:

An ion is a charged atom or molecule. It is charged because the number of electrons do not equal the number of protons in the atom or molecule. An atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.

Yes, I believe that people should keep trying. As many attempt we made as nearest possible outcome we get.

As we know that, practice make a man perfect. If we stop doing practices in the believe that this work is impossible then we never make it possible. But if we keep trying we always get outputs. Most scientists believe that perpetual-motion devices can never be invented, but people come up with new ideas for them all the time. Be always be confidence.

In this example we see that if people not think about making such type of device it never been happen. There is no shortcut way to obtain great goal. We never give up or lose our hope in just one attempt.

Thus I concluded that people should keep trying. As many attempt we made as nearest possible outcome we get. Do as many time until you not reach to your goal.

learn more about to achieve goals:

https://brainly.com/question/14801185

#SPJ13

Karl's leg cramp is unlikely to be caused by lactic acid, and the chemical equation for the process he is thinking of is C₆H₁₂O₆ + 2 ATP → 2 C₃H₃O₃⁻ + 2 NADH, option B is correct.

Karl's assumption that lactic acid is responsible for his leg cramp is a common misconception. In reality, lactic acid is a byproduct of anaerobic respiration, which occurs when there is not enough oxygen available to support aerobic respiration.

The process of glycolysis, which is the breakdown of glucose to pyruvate with the help of ATP. This process occurs in the cytoplasm of cells and is the first step in cellular respiration. The two pyruvate molecules produced by glycolysis can then be further broken down in the mitochondria to produce ATP through aerobic respiration, option B is correct.

To learn more about lactic follow the link:

brainly.com/question/4596922

#SPJ4

The complete question is:

Karl is at the gym exercising. After a while on the treadmill, he gets a cramp in his legs. Karl blames lactic acid building up in his muscles. What is the chemical equation for this process?

A) C₆H₁₂O₆ + 2 ADP + 2 Pi → 2 C₃H₆O₃ + 2 ATP

B) C₆H₁₂O₆ + 2 ATP → 2 C₃H₃O₃⁻ + 2 NADH

C) C₃H₃O₃⁻ + CoA + NAD+ → Acetyl-CoA + CO₂ + NADH

D) Acetyl-CoA + 3 NAD+ + FAD + GDP + Pi → 2 CO₂ + 3 NADH + FADH₂ + GTP

Therefore, approximately 226 grams of dry NH4Cl is needed to prepare a buffer solution with a pH of 8.93.

How to prepare a buffer solution?

To find out how many grams of dry NH4Cl need to be added to 2.50 L of a 0.800 M solution of ammonia, NH3, to prepare a buffer solution that has a pH of 8.93, follow these steps:

1. Calculate the pOH: pOH = 14 - pH = 14 - 8.93 = 5.07
2. Calculate the concentration of OH- ions: [OH-] = 10^(-pOH) = 10^(-5.07) ≈ 8.51 x 10^-6 M
3. Use the Kb expression for ammonia: Kb = [NH4+][OH-] / [NH3]
4. Rearrange the expression to find the concentration of NH4+: [NH4+] = Kb * [NH3] / [OH-]
5. Substitute the given values: [NH4+] = (1.8 x 10^-5) * (0.800) / (8.51 x 10^-6) ≈ 1.69 M
6. Calculate the moles of NH4+ needed: moles of NH4+ = 1.69 M * 2.50 L ≈ 4.22 mol
7. Convert moles of NH4+ to grams: grams of NH4Cl = moles * molar mass of NH4Cl ≈ 4.22 mol * 53.49 g/mol ≈ 226 g

Therefore, approximately 226 grams of dry NH4Cl need to be added to the 2.50 L solution of ammonia to prepare a buffer solution with a pH of 8.93.

To know more about Buffer Solutions:

https://brainly.com/question/29838557?

#SPJ11

Answer: because without them we can't produce any type of substances as for producing new products physical or chemical change is necessary

Explanation:

Butane < acetone < 1-propanol  is a list of the compounds in order of increasing boiling points.

The intermolecular interactions between molecules in a compound play a major role in boiling point. Higher boiling temperatures are a result of greater intermolecular interactions, bigger masses, and less branching.

The highest boiling point is for HF. As we go from HF to HI, the van der Waals forces of attraction between all hydrogen halides get stronger.

Boiling point rises as the difference in electronegativity grows. Additionally, the bp grows as the molecule's size does. So the sequence is CO2, CS2, CCl4, and then H2O.

Van der Waals attraction and dipole-dipole attraction draw acetone molecules together.

To learn more about compounds refer to:

https://brainly.com/question/26487468

#SPJ1

The equation which represents the second ionization energy of magnesium is Mg⁺ (g) -> Mg²⁺ (g) + e₋.

Ionization energy is defined as the minimum amount of energy required to remove an electron which is loosely held in the outermost shell to form an isolated gaseous atom,ion or molecule.

It has a positive value for neutral atoms indicating that the ionization process is an endothermic process . The closer the outermost shell electrons are to the nucleus of an atom higher is it's ionization energy.It is expressed in electron volts or joules.

Learn more about ionization energy,here:

https://brainly.com/question/28385102

#SPJ1

Answer:

Copper

Explanation:

Takealot excels at providing convenience, extensive product selection, competitive pricing, and a seamless online shopping experience as its value proposition for consumers.

Convenience is a key aspect of Takealot's value proposition. As an online retailer, Takealot offers the convenience of 24/7 shopping from the comfort of one's own home.

Customers can browse a wide range of products, place orders, and have them delivered directly to their doorstep.

Takealot also offers an extensive product selection, spanning various categories such as electronics, fashion, home goods, and more.

This breadth of choices allows consumers to find and compare different products all in one place, saving them time and effort compared to traditional retailers with limited inventory.

Competitive pricing is another area where Takealot excels. By operating online, the company has lower overhead costs compared to brick-and-mortar retailers, enabling them to offer competitive prices and discounts to their customers.

The seamless online shopping experience provided by Takealot includes user-friendly interfaces, secure payment options, and efficient delivery services. This enhances customer satisfaction and convenience.

In contrast, traditional non-online retailers typically have limited operating hours, smaller product selections, and may not offer the same level of convenience and competitive pricing.

They often require customers to physically visit their stores, which can be time-consuming and may not provide the same level of ease and accessibility as online platforms like Takealot.

To know more about "Customer satisfaction " refer here:

https://brainly.com/question/32142022#

#SPJ11

When excess copper carbonate is added to sulfuric acid, three observations that you may make are Fizzing or bubbling, Temperature change and Color change.

When excess copper carbonate is added to sulfuric acid, three observations that you may make are:

Fizzing or bubbling: When the copper carbonate reacts with the sulfuric acid, carbon dioxide gas is produced, which can cause fizzing or bubbling in the solution.

Temperature change: The reaction between copper carbonate and sulfuric acid is exothermic, meaning it releases heat. Therefore, you may observe a temperature change in the solution, with the temperature increasing.

Color change: Initially, the copper carbonate is green, and the sulfuric acid is colorless. As the reaction proceeds, the solution turns blue as copper sulfate crystals form.

To figure out the answer to this question, you would need to perform the experiment and make the observations yourself. You would need to add excess copper carbonate to a container of sulfuric acid and observe any fizzing, temperature change, and color change that occurs.

Learn more about salts here https://brainly.com/question/13818836

#SPJ1

The number of moles of calcium atoms in a tablet would be 0.015 moles. Option A.

The number of moles in a particular mass of substances is the ratio of the mass of the substances and their molar masses.

Mole = mass/molar mass

The molar weight of calcium is 40 amu.

For 0.6 g of calcium:

Mole = 0.6/40

         = 0.015 mol

In other words, the number of moles of calcium atoms in a tablet would be 0.015 moles.

More on the number of moles can be found here: https://brainly.com/question/12513822

#SPJ1

Answer:Observable properties are characteristics or things about materials or objects that we can describe using our five senses. Color, texture, hardness, and flexibility are all things we can determine with our senses.

Explanation:

Answer:

the area went through major changes in climate over geologic time

Explanation:

Different types of sediment is a good indication of different climates.For example, if an area just experienced the same type of climate, like a desert, we would expect to observe the same types of sediment/rocks in the area

Hope this helps :D

Answer: In metallic bonding, valence electrons can move freely between atoms

Explanation:

when metals bond to one another, their outermost energy levels overlap. this allows valence electrons to move freely between atoms in what is sometimes called a “sea of electrons

Answer:

  802.69 g

Explanation:

The molar mass of Barium nitrite is 229.34 g/mol, so 3.5 moles of it will have a mass of ...

  3.5 mol × 229.34 g/mol = 802.69 g

The reaction is the example of combustion reaction.

CH₄ + 2O₂ → CO₂ + 2H₂O

Burning or combustion is a highly heated exothermic reaction. It occurs when a fuel and oxygen (an oxidant) combine, releasing gaseous byproducts that are also known as smoke. A saturated open chain hydrocarbon with carbon-carbon single bonds is referred to as an alkane.

Alkane releases a tremendous amount of heat energy when heated in the presence of enough oxygen or air to form carbon dioxide and water. If the combustion reaction takes place in insufficient oxygen produces poisonous gases carbon monoxide.

Hence, combustion is complete burning to form water and carbon dioxide.

To know more about Balanced reaction.

https://brainly.com/question/14280002

#SPJ4