pls answer these questions for brainliest

katya is investigating displacement reactions . She heats the pairs of substances in this list

iron and aluminium oxide
iron and copper oxide
copper and magnesium oxide
iron and lead oxide

a)write down the letters os 2 pairs of substances that react . Explain your choices

b) choose one pair of substances that react . write a word equation for the reaction​

Answer:

1. Not to have enough salt water on the foil

2.not cleaning the foil well to remove interfering materials

Answer:

Alcl3 and Cl2

Explanation:

the product above will be formed

Answer:

silver (Ag) and aluminum chloride (AlCl₃)

Explanation:

The reaction between aluminum and silver chloride is a single replacement reaction. A single replacement reaction is when one element switches places with another.

Al + 3AgCl ➔︎ 3Ag + AlCl₃

In the reaction, the cations (positively charged ions) switch places. Aluminum (Al) switches places with Silver (Ag). So, the products of the reaction are silver and aluminum chloride.

Hope this helps.

Answer:

#1

Explanation:

molarity of EDTA solution 0.0675

no1

Answer:

THE MOLARITY OF THE SOLUTION IS 0.1039 MOL/DM3

Explanation:

Molarity is the number of moles of solute in a given solution,

Molarity in mol / dm3 = Molarity in g/dm3 / Molar mass

Mass = 15.2 g

Volume of solution = 2.5 l

Molar mass  of NaCl = (23 + 35.5) = 58.5 g/mol

First, we calculate the molarity in g/dm3

Molarity in g/dm3 = mass /volume

= 15.2 g * 1 L  / 2.5 L

=6.08 g /dm3

Hence, we will introduce the values and solve for molarity in mol/dm3

Molarity = 6.08 g/dm3/ 58.5 g/mol

Molarity = 0.1039 mol/dm3

The molarity of the solution is 0.1039 mol/dm3

Answer:

E 1: cyclohexene

Explanation:

This reaction is an example of the dehydration of cyclic alcohols. The reaction proceeds in the following steps;

1) The first step of the process is the protonation of the cyclohexanol by the acid. This now yields H2O^+ attached to the cyclohexane ring.

2) the water molecule, which a good leaving group now leaves yielding a carbocation. This now leaves a cyclohexane carbocation which is highly reactive.

3) A water molecule now abstracts a proton from the carbon adjacent to the carbocation leading to the formation of cyclohexene and the regeneration of the acid catalyst. This is an E1 mechanism because it proceeds via a carbocation intermediate and not a concerted transition state, hence the answer.

Answer:

2 CH₃OH  +  3 O₂  ⇒  2 CO₂  +  4 H₂O

Explanation:

Methanol is CH₃OH.  Oxygen is O₂.  A combustion produces CO₂ and H₂O.  Create an equation using this information and balance.

CH₃OH  +  O₂  ⇒  CO₂  +  H₂O

2 CH₃OH  +  3 O₂  ⇒  2 CO₂  +  4 H₂O

The balanced equation for the combustion of liquid methanol in air, assuming H2O(g) as a product is

CH₃OH(l) + O₂(g) → CO₂(g) + H₂O(g)

From the question,

We are to write a balanced equation for the combustion of liquid methanol in air.

The combustion of liquid methanol in air is the reaction between methanol (CH₃OH) and oxygen (O₂). The reaction yields carbon(IV) oxide and water.

Now, for the balanced equation for the combustion of liquid methanol in air

The balanced chemical equation is

CH₃OH(l) + O₂(g) → CO₂(g) + H₂O(g)

Hence, the balanced equation for the combustion of liquid methanol in air, assuming H2O(g) as a product is CH₃OH(l) + O₂(g) → CO₂(g) + H₂O(g)

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Answer:

THE MASS OF 7.68 *10^24 MOLECULES OF PHOSPHORUS TRICHLORIDE IS 1746.25 g.

Explanation:

Molar mass of PCl3 = ( 31 + 35.5 *3) = 137.5 g/mol

At 7.68 * 10^24 molecules, how many number of mole is present?

6.03 * 10^23 molecules = 1 mole

7.68*10^24 molecules = x mole

x mole = 7.68 *10^24 molecules/ 6.03 *10^23

x mole = 1.27 *10 moles

x mole = 12.7 moles

Using mole = mass / molar mass

mass = mole * molar mass

mass = 12.7 moles * 137.5 g/mol

mass = 1746.25 g

Hence, the mass of 7.68 *10^24 molecules is 1746.25 g

Answer: CO2(g)+H2O(I) > H2CO3(Aq)

Explanation:

Got it right?

Answer:

160.53L

Explanation:

Since Pressure is kept constant we can use charles law

Answer:

The balanced equation is :

NH4NO2(solid) = N2(gas) + 2 H2O(liquid)

Explanation:

A balanced chemical equation is an equation that has an equal number of atoms and charges on both sides of the equation. The given equation in question is imbalanced as the number of atoms not equal.

In this reaction, solid ammonium nitrite breaks into nitrogen gas and water, reaction known as decomposition.

The correct and balanced equation as follows :

NH4NO2(s) = N2(g) + 2 H2O(l)

Answer:

You require 12.8mL of the 0.500M C₂H₃O₂Na and 7.2mL of the 0.500M C₂H₃O₂H

Explanation:

It is possible to obtain pH of a weak acid using H-H equation:

pH = pKa + log₁₀ [A⁻] / [HA]

For the buffer of acetic acid/acetate, the equation is:

pH = pKa + log₁₀ [C₂H₃O₂Na] / [C₂H₃O₂H]

Replacing:

5.00 = 4.75 + log₁₀ [C₂H₃O₂Na] / [C₂H₃O₂H]

1.7783 =  [C₂H₃O₂Na] / [C₂H₃O₂H] (1)

Buffer strength is the concentration of the buffer, that means:

0.1M = [C₂H₃O₂Na] + [C₂H₃O₂H] (2)

Replacing (2) in (1):

1.7783 =  0.1M - [C₂H₃O₂H] / [C₂H₃O₂H]

1.7783 [C₂H₃O₂H] = 0.1M -  [C₂H₃O₂H]

2.7783 [C₂H₃O₂H] = 0.1M

Also:

[C₂H₃O₂Na] = 0.1M - 0.036M

The moles of both compounds you require is:

[C₂H₃O₂Na] = 0.1L × (0.064mol / L) = 0.0064moles

[C₂H₃O₂H] = 0.1L × (0.036mol / L) = 0.0036moles

Your stock solutions are 0.500M, thus, volume of both solutions you require is:

[C₂H₃O₂Na] = 0.0064moles × (1L / 0.500M) = 0.0128L = 12.8mL

[C₂H₃O₂H] = 0.0036moles × (1L / 0.500M) = 0.0072mL = 7.2mL

THIS IS THE COMPLETE QUESTION

Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid, HCl(aq), as described by the chemical equation.

How much MnO2(s) should be added to excess HCl(aq) to obtain 185 mL of Cl2(g) at 25 °C and 715 Torr?

Answer:

0.62901mol of MnO2(s) should be added

Explanation:

Given:

P = 715/760 = 0.94078atm

v=195ml=0.195l

n = ? moles have to find

R = 0.0821 L atm/K/mole

T = 25 + 273 = 298 K

Then we will make use of below formula

PV = nRT

Insert the values

0.94078*0.195=n 0.0821*298

24.466n=0.1740443

n=0.174/24.466

n=0.007235 nb of moles of cl2

as 1 mole of Cl2 were obtained from 1 mole of MnO2

so 0.007235 of chlorine must have come from

0.007235 moles of MnO2

1 mole of MnO2 = 86.94 g/mole

so 0.007235 moles of MnO2== 86.94* 0.007235

=0.62901

Answer:

322

Explanation:

This is easy

Answer:

198.56g of GaCl3

Explanation:

We'll begin by calculating the number of mole HCl in 2.25 L of a 1.50 M solution of HCl. This is illustrated below:

Molarity of HCl = 1.50 M

Volume = 2.25 L

Mole of HCl =..?

Molarity = mole /Volume

1.5 = mole /2.25

Cross multiply

Mole = 1.5 x 2.25

Mole of HCl = 3.375 mole

Next, we shall determine the number of mole Gallium chloride, GaCl3 produced from the reaction. This is shown below:

2Ga + 6HCl —> 2GaCl3 + 3H2

From the balanced equation above,

6 moles of HCl reacted to produce 2 moles of GaCl3.

Therefore, 3.375 mole of HCl will react to produce = (3.375 x 2)/6 = 1.125 mole of GaCl3.

Therefore, 1.125 moles of GaCl3 were produced from the reaction.

Next, we shall convert 1.125 mole of GaCl3 to grams. This is illustrated below:

Molar mass of GaCl3 = 70 + (35.5x3) = 176.5g/mol

Mole of GaCl3 = 1.125 mole

Mass of GaCl3 =..?

Mole = mass /Molar mass

1.125 = mass of GaCl3 /176.5

Cross multiply

Mass of GaCl3 = 1.125 x 176.5

Mass of GaCl3 = 198.56g

Therefore, 198.56g of GaCl3 were produced from the reaction.

Answer:

2 PbS(s) + 1.5 O₂(g) + PbO(s) ⇒ 2 SO₂(g) + 3 Pb(s)

Explanation:

Lead can be prepared from galena [lead(II) sulfide] by first heating with oxygen to form lead(II) oxide and sulfur dioxide. The corresponding chemical equation is:

PbS(s) + 1.5 O₂(g) ⇒ PbO(s) + SO₂(g)

Heating the metal oxide with more galena forms the metal and more sulfur dioxide. The corresponding chemical equation is:

2 PbO(s) + PbS(s) ⇒ 3 Pb(s) + SO₂(g)

We can get the overall reaction by adding both steps and canceling what is repeated on both sides.

2 PbS(s) + 1.5 O₂(g) + 2 PbO(s) ⇒ PbO(s) + 2 SO₂(g) + 3 Pb(s)

2 PbS(s) + 1.5 O₂(g) + PbO(s) ⇒ 2 SO₂(g) + 3 Pb(s)

Answer:

The answer is option D.

Hope this helps you

Answer:

lithium is akali metal

Answer:

lithium is an alkali metal as it lies in group 1st in modern perodic table.

Answer:

none of these statements is true

according to the question E) None of these statements is true.

The concentration of a chemical substance expresses the amount of a substance present in a mixture. There are many different ways to express concentration. Chemists use the term solute to describe the substance of interest and the term solvent to describe the material in which the solute is dissolved

Quantitative units of concentration include molarity, molality, mass percentage, parts per thousand, parts per million, and parts per billion.

Learn more about concentration here

https://brainly.com/question/24595796

#SPJ2

Answer:

The type of mixture whose components are seen through our naked eyes is known as heterogeneous mixture. it is a mixture of small constituent parts of substances.

for eg, mixture of sand and sugar.

hope it helps..

Answer:

C. the evolution of building techniques

Hope this helps.

Answer:

A. Partial pressure of krypton, Kr is 346.97 mmHg

B. Partial pressure of nitrogen, N2 is 364.03 mmHg.

Explanation:

Step 1:

Data obtained from the question. This include the following:

Total pressure (Pt) = 711 mmHg

Mass of Kr = 11.7 g

Mass of N2 = 4.10 g

Partial pressure of Kr =..?

Partial pressure of N2 =...?

Step 2:

Determination of the number of mole of krypton, Kr and nitrogen, N2. This is illustrated below:

Molar mass of Kr = 84g/mol

Mass of Kr = 11.7g

Mole of Kr =?

Mole = mass /Molar mass

Mole of Kr = 11.7/84 = 0.139 mole

Molar mass of N2 = 2x14 = 28g/mol

Mass of N2 = 4.10g

Mole of N2 =?

Mole = mass /Molar mass

Mole of N2 = 4.1/28 = 0.146 mole

Step 3:

Determination of the mole fraction for each gas. This is illustrated below:

Mole of Kr = 0.139 mole

Mole of N2 = 0.146 mole

Total mole = 0.139 + 0.146 = 0.285 mole

Mole fraction of Kr = mol of Kr/total mol

Mole fraction of Kr = 0.139/0.285

Mole fraction of Kr = 0.488

Mole fraction of N2 = mol of N2/total mol

Mole fraction of N2 = 0.146/0.285

Mole fraction of N2 = 0.512

A. Determination of the partial pressure of krypton, Kr.

This is illustrated below:

Total pressure (Pt) = 711 mmHg

Mole fraction of Kr = 0.488

Partial pressure of Kr =..?

Partial pressure = mole fraction x total pressure

Partial pressure of Kr = 0.488 x 711

Partial pressure of Kr = 346.97 mmHg

B. Determination of the partial pressure of nitrogen, N2

This is illustrated below:

Total pressure (Pt) = 711 mmHg

Mole fraction of N2 = 0.512

Partial pressure of N2 =?

Partial pressure = mole fraction x total pressure

Partial pressure of N2 = 0.512 x 711

Partial pressure of N2 = 364.03 mmHg

Answer: The solubility of gas increases in a solution if the pressure above the solution is increased

Explanation:

Henry's law states that the amount of gas dissolved or molar solubility of gas is directly proportional to the partial pressure of the liquid.

To calculate the molar solubility, we use the equation given by Henry's law, which is:

[tex]C=K_H\times p[/tex]

where,

C = solubility

[tex]K_H[/tex] = Henry's constant

p = partial pressure

As the solubility is directly proportional to the pressure, thus increasing the pressure increases the solubility.

Answer:

1. It dissolves much more ice faster than sodium chloride

2. Calcium chloride is more effective in melting ice at lower temperatures.

Explanation:

Salts are used to melt ice on roadways and sidewalks because they help to lower the freezing point of water.

Sodium chloride and calcium chloride are both salts used for this purpose but calcium chloride is usually preferred for the following two reasons:

1. It dissolves much more ice faster than sodium chloride: Calcium chloride dissolves much more ice faster than sodium chloride because when it dissociates, it produces three ions instead of the two produced when sodium chloride. Therefore, the heat of hydration of its ions is greater than that of sodium chloride.

2. Calcium chloride is more effective in melting ice at lower temperatures. It lowers the freezing point of water more than sodium chloride. Calcium chloride is able to lower the freezing point of water to about -52°C while sodium chloride only lowers it to about -6°C.

Answer:

filter the hot mixture.

Explanation:

Solid is stayed undissolved since the arrangement is gotten super saturated. On the off chance that solid molecule is available recrysallization won't happen in this way we need expel the solid molecule by filtarion in hot condition itself . Subsequently, arrangement become totally homogenous and recrysallization item will shaped by moderate cooling

Answer:

J

Explanation:

Answer:

CaC₂  +  2H₂O  →  C₂H₂  + Ca(OH)₂

Explanation:

In order to find out the reaction, we must know the reactants.

For this situation, we make acetylene gas from carbide calcium CaC₂ and H₂O (water); therefore the reactants are:

- CaC₂  and  H₂O

Acetylene is one of the products made  →  C₂H₂

So the reaction can be formed as this:  CaC₂  +  H₂O  →  C₂H₂

We missed the calcium, and this reaction also makes, Calcium Hydroxide, so the complete equation must be:

CaC₂  +  H₂O  →  C₂H₂  + Ca(OH)₂

This is unbalanced, because we have 1 O in left side and 2 in right side so we add 2 in water so now, we get the complete reaction:

1 mol of calcium carbide reacts to 2 mol of water in order to produce 1 mol of acetylene and 1 mol of calcium hydroxide.

Answer:

[tex]0.688M[/tex]

Explanation:

Hello,

In this case, it is widely acknowledged that strong bases usually correspond to those formed with metals in groups IA and IIA which have relatively high activity and reactivity, therefore, when they are dissolved in water the following dissociation reaction occurs (for calcium hydroxide):

[tex]Ca(OH)_2\rightarrow Ca^{2+}+2OH^-[/tex]

In such a way, for the same volume, we can compute the concentration of hydroxyl ions by simple stoichiometry (1:2 molar ratio):

[tex]0.344\frac{molCa(OH)_2}{L}*\frac{2molOH^-}{1molCa(OH)_2} \\\\0.688\frac{mol OH^-}{L}[/tex]

Or simply:

[tex]0.688M[/tex]

Regards.

Answer:

95.7 g CO to the nearest tenth.

Explanation:

2C + O2 ---> 2CO

Using relative atomic masses:

24 g C produces  2*12 + 2*16 g CO.

So 41 g produces  ( (2*12 + 2*16) * 41  ) / 24

= 95.7 g CO,

Answer:

2415.9g (corrected to 1 d.p.)

Explanation:

(Take the atomic mass of Ga=69.7 and S=32.1)

Assuming Ga is the limiting reagent (because the question did not mention the amount of sulphur burnt),

From the balanced equation, the mole ratio of Ga:Ga2S3 = 4: 2 = 2: 1, which means, every 2 moles of Ga burnt, 1 mole of Ga2S3 is produced.

Using this ratio, let y be the no. of moles of Ga2S3 produced,

[tex]\frac{2}{1} =\frac{20.5}{y}[/tex]

y = 20.5 / 2

= 10.25 mol

Since mass = no. of moles x molar mass,

the mass of Ga2S3 produced = 10.25 x (69.7x2 + 32.1x3)

= 2415.9g (corrected to 1 d.p.)

Answer:

54

Explanation:

Mass number = protones + neutrons

Mass number = 24 + 30

Mass number = 54