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What is wrong with the experimental design is that the student changed more than one independent variable.

WHAT AN EXPERIMENT SHOULD CONTAIN?

In the experiment conducted by the student in this question in order to determine how the temperature of water affects the time for sugar to dissolve. The independent variable is the DIFFERENT TEMPERATURE OF WATER while the dependent variable is the TIME TAKEN FOR SUGAR TO DISSOLVE.

N.B: An experiment should have only one independent variable and all other variables should be kept constant. This is to have a reliable result.

Therefore, the fact that the student changed more than one independent variable is wrong for the experimental design.

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Answer:

The student changed too many variables.

Explanation:

in k-12 took the quiz

Answer:

A. 35

B. 7

C. halogênios

Explanation:

Aqui, para responder a essa pergunta, precisaremos conhecer o elemento particular em questão.

..... 4s ^ 2 3d ^ 10 4p ^ 5 significa que está a cinco elétrons da configuração eletrônica do último elemento na primeira camada dos metais pesados.

O último elemento da 1ª série do elemento de transição é o zinco, portanto, como está a apenas 5 elementos de distância, o átomo de que estamos falando é o átomo de Bromo de Bromo.

A. O zinco tem um número atômico 30 e como o bromo está a 5 elementos de distância, seu número atômico é 35

B. Uma vez que pertence ao grupo halogênio, tem 7 elétrons de valência como o resto da família

C. Pertence à família dos halogênios

Answer:

≈ 0.70 g/cm³ (answer rounded up to 2 decimal places)

Explanation:

The mass of empty cylinder is 20g

The mass of water filling the cylinder = 30g - 20g = 10g

The mass of unknown liquid filling the cylinder = 27g - 20g = 7g

Density of water = 997 kg/m³

Converting this density to g/cm³ we get;

1kg = 1000g , 1m³ = 1000000cm³

So density = [tex]\frac{997000}{1000000}[/tex] g/cm³ = 0.997 g/cm³

So the volume of water occupied by 10g is;

10 × 0.997 = 9.97 cm³

This volume is also occupied by 7g of the unknown liquid.

Density = mass/volume

Density of the unknown liquid = 7g ÷ 9.97cm³ = 0.702106319 g/cm³ ≈ 0.70 g/cm³ (answer rounded up to 2 decimal places)

Answer:

C I think. If I am wrong please correct me.

Explanation:

Answer:

d

Explanation:

Housekeeping is the answer :)

Answer: Fe hóa trị II trong các hợp chất: FeSO4, Fe(OH)2

Fe hóa trị III trong các hợp chất: Fe2(SO4)3, Fe(OH)3

Explanation:

Answer:

composition of soda-lime glass is 73% SiO2 – 15% Na2O − 7% CaO − 4% MgO − 1% Al2O3 [129,132,133].

The Soda glass formula is SiO2, Na2O, CaO, Al2O3, K2O, SO3, MgO, Fe2O3, TiO2

Soda glass is a chemical compound that stands out for being the most widely used material to make windows, bottles, glasses, among others.

This compound is characterized by being chemically stable, reasonably hard, and extremely versatile because it can be recycled since it can be melted to make new products.

Its chemical formula is made up of other compounds such as:

Additionally, the compounds found in the highest proportion in glass are SiO2 (74 atoms) and Na2O (13 atoms).

Learn more in: https://brainly.com/question/1247523

Answer:

D.Something that can be observed or measured without changing the identity of the substance.

Answer:

Starch solution

Explanation:

Colloidal solutions show tyndall effect and starch solution is a colloidal solution.

Your question has been heard loud and clear.

The reaction of an acid with an alkali is neutralization reaction. It is a neutralization reaction because , they both neutralize each other (means it makes them chemically inactive after reacting) and produce a salt , and maybe water too.

An example: hydrochloric acid + sodium hydroxide → sodium chloride + water

Thank you

it will neutralise because if you add both of them together with a matching Ph such as 5 and 9 equally then it will neutralise and have a Ph of 7

could you please make me brainliest

Explanation:

Because chemistry deals with the structure of matter (such as the structure of the atom, it is related to physics. ... Because geology involves study of the matter the Earth and other bodies in the solar system are made of, geology involves chemistry. Geochemistry is the study of Earth materials, and how they change.

Answer: A. ( VO2)

Explanation:

Answer:

B) VO

Vanadium(II) oxide is the inorganic compound with the idealized formula VO.

Answer:

[tex]\huge\boxed{\sf D = 7.8 \ g/cm^3}[/tex]

Explanation:

Density = Mass / Volume

Where Mass = 39 g and Volume = 5 cm³

So,

[tex]\sf Density = \frac{39}{5} \\Density = 7.8 g/cm^3[/tex]

Answer:

Producer gas and water gas contain carbon monoxide and hydrogen.

Answer:

CuO+2HCl>h2o+CuCl2

fe203+6hcl->2fecl3+3h2O

gọi CuO, fe2o3 lần lượt là x,y

80x+160y=10

2x+6y=0.35

giải phương trình ta dc hai số x,y(tính phương trình kia ra)

cuo ban đầu sẽ là :60*x=z

fe203 ban đầu sẽ là :10-z=

Explanation:

Answer:

1a) .68 moles 1b)4.1E-23 molecules.

2a) .37 moles 2b) 2.27E-23 molecules

Explanation:

1a) CO2 is equal to 44 grams (C→12 grams,O→16 grams[·2]) .30g/44g is .68 moles.

1b) multiply 1A by advogadros number (6.022E-23)

2a) NaCl is 58 grams. 22/58 is .37 moles.

2b) multiply 2A by advogadros number.

you'd answer #3 the same way #1 and #2

The branch of science that deals with chemicals and bonds are called chemistry. The moles are units to calculate the quantity required to use the element.

The correct answer is mentioned below.

According to the question, the moles to the option is as follows:-

[tex]n =\frac{M}{M.M}\\ \\\frac{30}{44} \\\\=0.681\\\\[/tex]

The number of molecules is [tex]0.68 *6022*10^{23} =4.09496*10^{23[/tex].

2. moles of 22 grams of NaCl is

[tex]\frac{22}{44}\\ \\=0.5\\\\[/tex]

Molecules will be [tex]0.5*6.022*10^{23} = 3.011*10^{23}[/tex]

3. moles of 50-gram ammonia

[tex]\frac{50}{17} \\\\2.94\\[/tex]

The number of molecules is [tex]2.94*6.022*10^{23} = 1770*10^{23[/tex]

For more information about the moles, refer to the link:-

https://brainly.com/question/15209553

Answer:

oxygen molecule has two oxygen atom . Each O atom share 2 electrons to form two covalent bonds out of which one is sigma bond and other is pi bond . sigma bond is formed by axial overlap 2p atomic orbitals of oxygen and pi bond is formed of lateral overlap of 2p atomic orbitals of oxygen .

Answer:

C

Explanation:

I believe the answer is C.

Answer:

+VE

Explanation:

If we look at the reaction profile pictured in the question, we can easily identify A as the enthalpy of the reaction. The enthalpy of reaction (ΔHrxn) is usually defined as the difference between the total enthalpy (heat content) of the products of a reaction and the total enthalpy (heat content) of the reactants in that reaction.

Looking at the figure, we can see that the enthalpy of products is greater than the enthalpy of reactants, hence ∆Hrxn is positive as stated in the answer above.

Answer:

Opposite.

Water exhibits negative charge near hydrogen, positive near oxygen.

This is why it is OPPOSITE.

Let me know if this helps!

Water is a polar compound because it exhibits opposite charges. Therefore, option C is correct.

The term polar compound is defined as the compound with distinct regions of positive and negative charge, as a result of bonding with atoms such as nitrogen, oxygen, or sulfur.

Water is a polar compound because the covalent bonds between hydrogen and oxygen in the water molecule are polar in nature. Any molecule with lone pairs of electrons around the central atom is polar compound.

In water there are two atoms are present that are oxygen and hydrogen. Hydrogen has positive charge while oxygen has negative charge,

Thus, Water is a polar compound because it exhibits opposite charges, option C is correct.

To learn more about the polar compound, follow the link;

https://brainly.com/question/14752836

#SPJ2

Answer:

This is because mechanical phase-separation device such as filtration, centrifugation etc operate according to the unique particle size feature in which they are designed to separates.

The process of centrifugation separates particles of size range between 0.1 μm to 5.0 μm efficiently.

The process of filtration however varies as there are different types of pore sizes which covers a wide range of particle sizes.

Answer:

1. The limiting reactant is H2O2.

2. The amount of excess reactant, N2H4 that remain unchanged is 11.15 moles.

3. 1.65 moles of N2.

4. 6.6 moles of H2O.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is given below:

N2H4 + 2H2O2 —> N2 + 4H2O

From the balanced equation above,

1 mole of N2H4 reacted with 2 moles of H2O2 to produce 1 mole of N2 and 4 moles of H2O.

1. Determination of the limiting reactant.

From the balanced equation above,

1 mole of N2H4 reacted with 2 moles of H2O2.

Therefore, 12.8 moles of N2H4 will react with = 12.8 x 2 = 25.6 moles of H2O2.

From the calculations made above, we can see that it will take a higher amount i.e 25.6 moles than what was given i.e 3.3 moles of H2O2 to react completely with 12.8 moles of N2H4.

Therefore, H2O2 is the limiting reactant and N2H4 is the excess reactant.

2. Determination of the excess reactant that remain unchanged.

The excess reactant is N2H4.

First, we shall determine the amount of the excess reactant that reacted. This is illustrated below:

From the balanced equation above,

1 mole of N2H4 reacted with 2 moles of H2O2.

Therefore, Xmol of N2H4 will react with 3.3 moles of H2O2 i.e

Xmol of N2H4 = (1 x 3.3)/2

Xmol of N2H4 = 1.65 moles

Therefore, 1.65 moles of N2H4 reacted.

Now, we shall determine the excess reactant that remain unchanged. This can be obtained as follow:

Amount of N2H4 given = 12.8 moles

Amount of N2H4 that reacted = 1.65 moles.

Amount of N2H4 that remain unchanged =?

Amount of N2H4 that remain unchanged = (Amount of N2H4 given) – (Amount of N2H4 that reacted = 1.65 moles)

Amount of N2H4 that remain unchanged = 12.8 – 1.65

Amount of N2H4 that remain unchanged = 11.15 moles.

3. Determination of the amount of N2 produced.

In this case, the limiting reactant will be used because it will give the maximum yield of N2 as all of it is used up in the reaction.

The limiting reactant is H2O2 and the amount of N2 produced can be obtained as follow:

From the balanced equation above,

2 moles of H2O2 reacted to produce 1 mole of N2.

Therefore, 3.3 moles of H2O2 will react to produce = (3.3 x 1)/2 = 1.65 moles of N2.

Therefore, 1.65 moles of N2 were obtained from the reaction.

4. Determination of the amount of H2O produced.

In this case, the limiting reactant will be used because it will give the maximum yield of H2O as all of it is used up in the reaction.

The limiting reactant is H2O2 and the amount of H2O produced can be obtained as follow:

From the balanced equation above,

2 moles of H2O2 reacted to produce 4 moles of H2O.

Therefore, 3.3 moles of H2O2 will react to produce = (3.3 x 4)/2 = 6.6 moles of H2O.

Therefore, 6.6 moles of H2O were produced from the reaction.

Answer:

The independent variable effects the dependent variable.

Explanation:

The independent variable Is what you change whereas the dependent variable would change because of that.

for example, the indipendent variable could be how much you water a plant in ml each day, and the dependent variable would be how tall each plant grown]s with that water doseage per day.

Answer:

Mass of chemical = 50 gram

Explanation:

Given:

Volume of chemical = 5 ml

Density of chemical = 10 g/mL

Find:

Mass of chemical

Computation:

Mass of chemical = Density of chemical × Volume of chemical

Mass of chemical = 10 × 5

Mass of chemical = 50 gram

Answer: D

Explanation:

Answer:

C.

Explanation:

It requires work to stretch or compress a spring.

Answer:the answer is c

Explanation: i say that because with work you can do both of those things

Answer:

50%

Explanation:

Expected measurement required = 10g

Actual measurement observed = 15g

The percentage error is given as proportion the difference between the actual and expected measurement or values and the expected value value expressed as a percentage.

[(Actual - Expected) / Expected] × 100%

[(15 - 10) / 10)] × 100%

(5 / 10) × 100%

0.5 × 100%

50%

Therefore, the percentage error in the measurement is 50%