give few property of PET​

Answer:

i) During washing

ii) During Measurement

Explanation:

The two possible steps are :

i) During washing : during the washing method the residue may be not completely dried out and this residue ( water) will add up to the final product ( copper yield ) and this kind of error is called human error.

ii) During measurement : If the weighing instrument is faulty there might be addition  in value of the final copper yield which will see the final yield value > 100% . this error occurs when the initial value and final value is  been weighed

Answer:

A heatwave occurs when a system of high atmospheric pressure moves into an area and lasts two or more days.

Explanation:

In such a high-pressure system, air from upper levels of our atmosphere is pulled toward the ground, where it becomes compressed and increases in temperature.

Answer: The number of moles of NaOH is 0.0036 moles

Explanation:

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

[tex]\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{ \text{Volume of solution (mL)}}[/tex] .....(1)

Given values:

Molarity of NaOH = [tex]0.1mol/dm^3=0.1mol/L[/tex]         (Conversion factor: [tex]1L=1dm^3[/tex]

Volume of the solution = [tex]36cm^3=36 mL[/tex]             (Conversion factor: [tex]1mL=1cm^3[/tex]

Putting values in equation 1, we get:

[tex]0.1=\frac{\text{Moles of NaOH}\times 1000}{36}\\\\\text{Moles of NaOH}=\frac{0.1\times 36}{1000}=0.0036mol[/tex]

Hence, the number of moles of NaOH is 0.0036 moles

Answer:

solutions are homogeneous mixtures of two or more solutes in a solvent

solubility is the ability of a solute to dissolve in a solvent

Explanation:

hope this is helpful

The question is incomplete, the complete question is:

Standardization of a Borax solution (Na2B4O7). A student titrates a 20.00 mL sample of an aqueous borax solution with 1.044 M H2SO4. It takes 2.63 mL of acid to reach the equivalence point. Knowing it takes 1 H2SO4 to neutralize 2 Na2B4O7, what was the concentration of this Borax solution?

Answer: The concentration of borax solution is 0.069 M.

Explanation:

To calculate the concentration of borax solution, the formula used is:

[tex]n_1C_1V_1=n_2C_2V_2[/tex] ....(1)

where,

[tex]n_1, C_1\text{ and }V_1[/tex] are the n-factor, concentration and volume of sulfuric acid

[tex]n_2,C_2\text{ and }V_2[/tex] are the n-factor, concentration and volume of borax solution.

We are given:

[tex]n_1=1\\C_1=1.044M\\V_1=2.63mL\\n_2=2\\C_2=?M\\V_2=20mL[/tex]

Putting values in equation 1, we get:

[tex]1\times 1.044\times 2.63=2\times C_2\times 20\\\\C_2=\frac{1\times 1.044\times 2.63}{2\times 20}\\\\C_2=0.069M[/tex]

Hence, the concentration of borax solution is 0.069 M.

Answer:

A: Gamma

Gamma rays have enough energy to kill bacteria

A. build proteins

Explanation:

The endoplasmic reticulum can either be smooth or rough, and in general its function is to produce proteins for the rest of the cell to function. The rough endoplasmic reticulum has on it ribosomes, which are small, round organelles whose function it is to make those proteins

Answer:

[tex]{ \boxed{ \tt{formular : pH = - log[H {}^{ + } ]}}} \\ pH = - log(1.00 \times {10}^{-6} ) = 6: it's an acid\\ since \: we \: lack \: the \: exponent, \: this \: question \: is \: unsolvable \\ { \green{ \bf{take \: note}}} :{ \tt{pH \: below \: 7 \: that \: is \: { \red{acidic}}. \: \: pH \: greater \: than \: 7 \: is \: { \red {basic}}}}[/tex]

Answer:

+1/2

Explanation:

spin up is always +1/2

Explanation:

A B C D isme koyi ans hain doond lo

Answer:

d. the solution is a acid

Answer:D The solution is an acid

Explanation:The lower the pH of a substance the stronger the acidic level.

Answer:

Weight = 500 Newton

Explanation:

Given the following data;

Acceleration due to gravity = 10N/Kg

Weight can be defined as the force acting on a body or an object as a result of gravity.

Mathematically, the weight of an object is given by the formula;

[tex] Weight = mg [/tex]

Where;

Note: In order to calculate the weight of a mass, it's required that the mass of an object or body is given.

However, in this particular question it was omitted in error and as such i would assume a value.

Substituting into the formula, we have;

[tex] Weight = 50 * 10 [/tex]

Weight = 500 Newton

Answer:

See explanation

Explanation:

Electroplating is a method used to coat a metal on top of another metal for various purposes.

Additive plating involves the coverage of a metal surface by another metal. To make the coins, the suspects had to coat the required coinage metal on another metal called the base metal so as to produce the coin.

Hence the method used must be additive plating method.

The addition of any non-volatile solutes will elevate the boiling point of the solution. The change in boiling point of water by the addition of 2.10 of barium chloride is 0.0028 ° C. Hence, option A is correct.

Boiling point of a substance is the temperature at which it changes from liquid to vapour where the two states are in equilibrium. Boiling point of a substance depends on the bond type, molecular mass and purity of it.

The change or elevation of boiling point of a solution can be determined from its molality m and elevation constant Kb and the Van't Hoff factor i as follows:

ΔT = i Kb m.

Molality of the solution is the no.of moles divided by the mass of solvent in kilogram. Given the mass of barium chloride is 2.10 g and its molar mass is 208.23 g . The no.of moles of solute is 2.10/208.23 g = 0.0100.

Molality of the solution can be calculated as follows:

Molality m = 0.0100 / 5.50 Kg

                 = 0.0018 mol/kg.

Now, the  ΔT s calculated from these values. Provided Kb of water is 0.51 ° C /mol and i = 3.

ΔT  = 0.0018 mol/kg × 0.51 × 3

       = 0.0028 ° C.

Therefore, water will boil at 100.0028 ° C. Hence, option A is correct.

To find more about boiling point, refer the link below:

https://brainly.com/question/28203474

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Answer:

A

Explanation:

because B is wrong as it doesn't have the same mass number. C is wrong as it has different number of neutrons. D is wrong as it has more neutrons than protons.

Answer:

Malleability describes the property of a metal's ability to be distorted below compression. It is a physical property of metals by which they can be hammered, shaped and rolled into a very thin sheet without rupturing. A malleable fabric could be planate by blow or rolling.

Explanation:

Ductility is the property of a solid, like a metal, to deform under a tensile stress (force). So if you pull on two ends of a metal wire or bar, and it “stretches” you have a ductile substance. Though I must caution that you don't confuse the definition of ductile to mean elastic. They are not synonyms. It is the opposite of brittle. When a ductile item breaks, it is after necking, where the diameter of the wire in question reduces as the length elongated. A brittle, or non-ductile material simple tears apart in a sharp and quick fashion with little to no visible necking taking place.

sonorous: producing sound (as when struck)

Answer:

43.8%

Explanation:

Find the sum of the relative atomic mass of all the elements constituting the compound, which is known as the relative formula mass;

[tex]M_{r} = Relative \ formula \ mass \\\\M_{r} \ of \ ZnSO_{4} = 65.4 + 32.1 + 4(16) \\\\M_{r} \ of \ ZnSO_{4} = 97.5 + 64 \\\\M_{r} \ of \ ZnSO_{4} = 161.5 \\\\M_{r} \ of \ H_{2}O = 18 \\\\M_{r} \ of \ ZnSO_{4}.7H_{2}O = 161.5 + 7(18) \\\\M_{r} \ of \ ZnSO_{4}.7H_{2}O = 287.5[/tex]

Then, divide the relative formula mass of all the water by that of the whole compound

w = % water

[tex]w = \frac{7(18)}{287.5} * 100 \\\\w = 0.43826... * 100\\\\w = 43.826...[/tex]

w = 43.8%

Explanation:

Objectives and goals serve as a foundation for successful organizations since they establish the business's objective and aid in the identification of required measures. Goals are broad assertions of what you want to achieve, whereas goals are the precise stages or steps you need to take to get there.

Answer:

The molecules of oxygen should be placed as reactants in the equation.

Explanation:

1:      N₂ + O₂ → 2NO

2:     2NO + O₂ → 2NO₂

complete reaction:

N₂ + 2O₂ → 2NO₂

We can not place oxygen at the side of products neither we can cancel it because, products can only be obtained at the end of the reaction but according to the equations' oxygen is not the end product of the reaction. But the addition into the reaction (Eq. 2) to make the new product.

Also, we can not cancel it because to cancel out molecules of oxygen should be present at the both sides with same amount in the stoichiometric equation.

Hence, in a balanced chemical equation, oxygen should be written as a reactant by using the correct number of moles.

Answer: That results in a different ALTERNATE pathway which has a LOWER ACTIVATION ENERGY.

Explanation:

There are many factors that affects a chemical reaction, these include'

--> surface area

--> concentration,

--> temperature,

--> pressure and

--> presence of CATALYST.

A CATALYST is defined as the substance that has the ability to alter the rate of a chemical reaction. Many reaction very slowly when left alone, but become faster when other substances are added. Such substances that merely alter the rate of reactions but do not take part in the reactions are called CATALYSTS.

Activation energy is defined as the energy barrier that must be overcome before a reaction takes place. A catalyst is able to increase the rate of a chemical reaction by decreasing the activation energy of the chemical system.

A catalyst provides an ALTERNATE PATHWAY for the reaction that has a LOWER ACTIVATION ENERGY. When activation energy is lower, more reactant particles have enough energy to react, so the reaction occurs faster.

Answer:

The final temperature aluminium-water system is 24° C

Explanation:

Heat energy, H = mcθ

Where m is mass of substance, c is specific heat capacity, θ is temperature difference

Using the principle, Heat lost = Heat gained

Let the final temperature of the aluminium-water system be Tfinal

Heat lost by aluminium, H₁ = -m₁c₁(Tfinal - 40)

Heat gained by water, H₂ = m₂c₂(Tfinal -21)

Heat lost by aluminium, H = -[30 × 0.21 × (Tfinal - 40)]

H₁ = -6.3Tfinal + 252

Heat gained by water, H₂ = 50 × 1.0 × (Tfinal - 21)

H₂ = 5Tfinal - 21

Equating H₁ and H₂

-6.3Tfinal + 252 = 5 Tfinal - 21

5Tfinal + 6.3Ffinal = 252 + 21

11.3 Tfinal = 273

Tfinal = 273/11.3

Tfinal = 24° C

Therefore, the final temperature aluminium-water system is 24° C

Answer:

C

Explanation:

In thermodynamics, a exothermic system looses heat to the surroundings while an endothermic system absorbs heat from the surroundings.

A system is a part the universe marked off by a specified boundary. The contents of the cup constitutes the system in this case.

The region of space outside the system is called the surroundings. Hence everything outside the cup constitutes the surroundings.

Answer:

It's answer is c) exactly 37 protons

Answer:

C) ,  Exactly 37 protons.

Explanation:

Remember the electrons have a negative charge, so to make a atom with 37 electrons neutral, you will need the same amount of the opposite type. That means you need 37 protons.

Answer:

4084.808 grams (SigFigs: 4085 grams)

Explanation:

The molar mass of Iron fluoride is 112.84 g/mol.

To calculate the mass, multiply the molar mass by the number of moles.

36.2 mol * 112.84 g/mol = 4084.808 g

Convert to Sigfigs (if necessary):

4085 g

Answer:

The person above is correct

Explanation:

c) Current cannot flow

Reason: Because the switch is not closed.

Answer:

current can't flow

Explanation:

by the way of explanation it is open circuit in which the current flow whereas in closed circuit the current flow.

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Answer:

C. Gravity only

Explanation:

Answer:

2.5×10⁶ s

Explanation:

From the question given above, the following data were obtained:

Rate constant (K) = 2.8×10¯⁷ s¯¹

Half-life (t½) =?

The half-life of a first order reaction is given by:

Half-life (t½) = 0.693 / Rate constant (K)

t½ = 0.693 / K

With the above formula, we can obtain the half-life of the reaction as follow:

Rate constant (K) = 2.8×10¯⁷ s¯¹

Half-life (t½) =?

t½ = 0.693 / K

t½ = 0.693 / 2.8×10¯⁷

t½ = 2.5×10⁶ s

Therefore, the half-life of the reaction is 2.5×10⁶ s

(i) Liang - liang stoma lebih banyak di bahagian bawah daun berbanding di bahagian atas permukaan daun.

(ii) Struktur X berfungsi mangawal pembukaan dan penutupan liang stoma

Answer: The molality of [tex]NaC_2H_3O_2[/tex] solution is 0.782 m

Explanation:

Molality is defined as the amount of solute expressed in the number of moles present per kilogram of solvent. The units of molarity are mol/kg. The formula used to calculate molality:

[tex]\text{Molality of solution}=\frac{\text{Moles of solute}}{\text{Mass of solvent (in kg)}}[/tex] .....(1)

Given values:

Moles of [tex]NaC_2H_3O_2[/tex] = 0.395 mol

Mass of solvent (water) = 0.505 kg

Putting values in equation 1, we get:

[tex]\text{Molality of }NaC_2H_3O_2=\frac{0.395mol}{0.505kg}\\\\\text{Molality of }NaC_2H_3O_2=0.782m[/tex]

Hence, the molality of [tex]NaC_2H_3O_2[/tex] solution is 0.782 m