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3 years ago

9

Investigating a fire scene, Investigator Smith determines several places where fires started. What might this indicate about the

cause of the fire? A) it was an electrical fire B) it was deliberately set C) an accelerant was used D) It was an accident

1 answer:

grigory [225]3 years ago

3 0

Answer:

an accelerant was used because maybe some was spilt and therefore leaving a smell and evidence

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slava [35]

1 Double displacement

2 A) a reaction in which the exchange of electrons (or oxygen) occurs

3 A) Silver has a lower activity than hydrogen and cannot replace it.

4 C) 2C₂H₆ + 7O₂ → 4CO₂ +6H₂O

5. two

6.C) redox

7.B) The ions of two ionic compounds switch places and a gas is formed.

Explanation:

Problem 1:

Equation of the reaction:

Na₂S + Cd(NO₃)₂→CdS + 2NaNO₃

The above reaction is a double displacement reaction in which ions of two ionic compounds changes position to form new products.

A double displacement reaction is also known as metathesis.

The reaction involves actual exchange of partners to form new products.
In most double displacement reactions, precipitates are usually formed.
There might also be formation of water and any non-ionizing compound.
liberation of a gaseous product.

Learn more:

precipitates brainly.com/question/8896163

Question 2

A) a reaction in which the exchange of electrons (or oxygen) occurs:

Redox reactions are reactions in which one species is reduced and another species is oxidized simultaneously.

In this reaction types, there is exchange of electrons between reacting species.
In non-redox reactions, there is no exchange or transfer of electrons.
Redox reactions involves the transfer of electrons in which a specie gains and the other loses.

Learn more:

Oxidation brainly.com/question/2086855

Question 3:

A) Silver has a lower activity than hydrogen and cannot replace it.

H₂O + Ag→no reaction

The reaction above is a single replacement reaction

The replacement of a metallic ion in solution by a metal higher in the activity series than the metal in solution is this kind of reaction.
The positions of the two elements in the activity series provides the driving force for this reaction.
Hydrogen is higher than Ag in the reactivity series.
Since hydrogen is more reactive, Silver cannot displace it and the reaction will not occur.

Learn more:

Reactivity brainly.com/question/2193659

Question 4:

4 C) 2C₂H₆ + 7O₂ → 4CO₂ +6H₂O

Solution:

C₂H₆ + O₂→CO₂+H₂O

For combustion reactions in hydrocarbons, we use the expression below:

CₓHₙ + x + $\frac{n}{4}$ O₂ → xCO₂ + $\frac{n}{2}$ H₂O

x = 2 , n = 6

x + $\frac{n}{4}$ = 2 + $\frac{6}{4}$ = $\frac{7}{2}$

$\frac{n}{2}$ = $\frac{6}{2}$ = 3

multiply the coefficients by 2:

2, 7, 4 and 6

learn more:

Combustion brainly.com/question/1971314

Question 5

four

2NaNO₃ + CaCl₂ → 2NaCl + Ca(NO₃)₂

To find the number of atoms of Na, we must understand what an atom really is;

An atom is the smallest particle of an atom that takes part in chemical reaction. Distinct elements are made up unique types of atoms.

In the above reaction, we have:

2moles of NaNO₃ on the left hand side:

we have 2 Atoms of Na,

2 atoms N

6 atoms of O

2 moles of NaCl contains:

2 atoms of Na

2 atoms of Cl

In all, we have 4 atoms of Na

learn more:

Atoms brainly.com/question/10216585

Question 6

C) redox

AgNO₃(aq)+Cu(s)→Ag(s)+Cu(NO₃)₂(aq)

In a redox reaction, a specie is reduced and another is oxidized in the reaction.

In this reaction, one specie loses electrons and the other gains it.
Certain reactants change their oxidation state so as to form products.

In the reaction above,

Ag undergoes reduction; it goes from Ag⁺ to Ag from a +1 to zero.

whereas Copper goes from O to 2+ oxidation state.

Actually, this reaction is more appropriately described as a single displacement reaction in which atom higher in the activity series displaces the lower one.

learn more:

Redox Oxidation brainly.com/question/2086855

Question 7:

B) The ions of two ionic compounds switch places and a gas is formed.

A double displacement reaction is also known as metathesis or double replacement reaction.
It usually involves ionic compounds.
The reaction involves an exchange of partners to form new compounds.

One of the following serves as driving force for double displacement reactions:

formation of an insoluble compound called precipitate
formation of water or any other non-ionizing compound
liberation of a gaseous product.

Learn more:

Precipitate formation brainly.com/question/8896163

#learnwithBrainly

7 0

3 years ago

Is gold a element or pure substance

Vadim26 [7]

Gold is a element. Hope this helps

3 0

4 years ago

Read 2 more answers

N2 (g) + 3 H2 (g) → 2 NH3 (g)

shusha [124]

This problem is asking for the rate of disappearance of gaseous nitrogen, given the rate of appearance of ammonia and the chemical reaction. At the end, the result turns out to be -0.228 M/s.

<h3>Rates of appearance and disappearance</h3>

In chemical kinetics, one of the most relevant calculations are based on rates of appearance and disappearance of chemical species in a chemical reaction. This can be calculated via rate portions based on the stoichiometric coefficients in the reaction.

Thus, for this problem, one can write:

$\frac{r_{N_2}}{-1} =\frac{r_{H_2}}{-3} =\frac{r_{NH_3}}{2}$

Where the rate of appearance or disappearance is divided by the stoichiometric coefficient. Therefore, one can solve for the rate of disappearance of N2 with:

$\frac{r_{N_2}}{-1} =\frac{r_{NH_3}}{2}\\\\r_{N_2}=\frac{r_{NH_3}*-1}{2}\\\\r_{N_2}=\frac{0.456M/s*-1}{2}\\\\r_{N_2}=-0.228M/s$

Learn more about chemical kinetics: brainly.com/question/26351746

3 0

2 years ago

If I have 7.0 x 10^24 formula units of magnesium chloride, how many grams of chlorine would I have?

REY [17]

Answer:

824 g

Explanation:

First we <u>convert 7.0 x 10²⁴ formula units of magnesium chloride (MgCl₂) into moles</u>, using <em>Avogadro's number</em>:

7.0 x 10²⁴ formula units ÷ 6.023x10²³ formula units/mol = 11.62 mol MgCl₂

There are two Cl moles per MgCl₂ moles, meaning that we have (2 * 11.62) 23.24 moles of Cl

Finally we <u>convert 23.24 moles of chlorine into grams</u>, using <em>chlorine's molar mass</em>:

23.24 mol * 35.45 g/mol = 824 g

3 0

3 years ago

In the electrolysis of molten BaI₂,(a) What product forms at the negative electrode?

Darya [45]

In the electrolysis of molten BaI₂, the product forms at the cathode Barium metal (Ba).

First ionic bonds in this salt are separated because of heat:

BaI₂(aq) → $Ba^{2+}$ (aq) + I⁻(aq).

Reaction of reduction at cathode(-):

$Ba^{2+}$ (aq) + 2e⁻ → 2Ba(s)

$Ba^{2+}$ turns into Ba metal.

Reaction of oxidation at anode(+):

2I⁻(aq) → I₂(g) + 2e⁻.

So I⁻ turns into I₂(g)

The anode is positive and the cathode is negative.

In chemistry, the type of process in which decomposition of a chemical substance occurs due to the flow of electricity through the substance is generally known as the electrolysis process. Usually, the electrolysis process becomes in an arrangement in which one electrode of the cathode and one electrode of the anode are present.

In chemistry and production, electrolysis is a technique that makes use of direct electric present-day (DC) to power an otherwise non-spontaneous chemical response.

Electrolysis is commercially crucial as a degree inside the separation of factors from clearly going on sources including ores the usage of an electrolytic cell.

To learn more about the electrolysis please click on the link : brainly.com/question/24063038

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3 0

2 years ago