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2 years ago

Explain how a substances flammability can indicate a chemical change.

Chemistry

1 answer:

Marat540 [252]2 years ago

4 0

Answer:

This is simple, if it has a high flammability, and you light it on fire, then that would be a chemical change.

Explanation:

May I have brainliest please? :)

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A container of argon with a volume of 22 ml has a pressure of 101.0 kPa.

Alexeev081 [22]

Answer:

The new pressure is 44.4 kPa.

Explanation:

We have,

Initial volume, $V_1=22\ ml$

Initial pressure, $P_1= 101.0\ kPa$

It is required to find the new pressure when the volume is increased to 50 ml. The relationship between pressure and volume is known as Boyle's law.

$PV=k\\\\P_1V_1=P_2V_2$

$P_2$ is final pressure

$P_2=\dfrac{P_1V_1}{V_2}\\\\P_2=\dfrac{22\times 101\times 10^3}{50}\\\\P_2=44440\ Pa\\\\P_2=44.4\ kPa$

So, new pressure is 44.4 kPa.

6 0

2 years ago

What is the percent composition by mass of oxygen in Ca(NO3)2 (gram-formula= 164 g/mol)?

Neko [114]

To find this, we will use this formula:

Molar mass of element
------------------------------------ x 100
Molar mass of compound

So, first lets calculate the mass of the compound as a whole. We use the atomic masses on the periodic table to determine this.

Ca: 40.078 g/mol
N2 (there is two nitrogens): 28.014 g/mol
O6 (there are six nitrogens: 3 times 2): 95.994 g/mol

When we add all of those numbers up together, we get 164.086. That is the molar mass for the whole compound. However, we are trying to figure out what percent of the compound oxygen makes up. From the molar mass, we know that 95.994 of the 164.086 is oxygen. Lets plug those numbers into our equation!

95.994
-----------
164.086

When we divide those two numbers, we get .585. When we multiply that by 100, we get 58.5.

So, the percent compostition of oxygen in Ca(NO3)2, or, calcium nitrate, is 58.5%.

5 0

3 years ago

Consider the reaction pathway graph below.

Alex17521 [72]

Hello!

The reaction that the graph represents is A. Exothermic because Hrxn=-167 kJ

To calculate Hrxn we apply the following equation:

$Hrxn=Hproducts-Hreagents=-625kJ-(-458kJ)=-167kJ$

Looking at the graph, and at the result of the calculations, we can see that the enthalpy of the products is lower than the enthalpy of the reagents, because the sign is negative. That means that the reaction releases energy in the form of heat and that the reaction is exothermic.

Have a nice day!

6 0

3 years ago

In a single displacement reaction between sodium phosphate and barium, how much of each product (in grams) will be formed from 1

weeeeeb [17]

Answer:

A. 3.36g of Na.

B. 14.62g of Ba3(PO4)2.

Explanation:

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

3Ba + 2Na3PO4 → 6Na + Ba3(PO4)2

Next, we shall determine the mass of Ba that reacted and the mass of Na and Ba3(PO4)2 produced from the equation.

This is illustrated below:

Molar Mass of Ba = 137g/mol

Mass of Ba from the balanced equation = 3 x 137 = 411g

Molar mass of Na = 23g/mol

Mass of Na from the balanced equation = 6 x 23 = 138g

Molar mass of Ba3(PO4)2 = (3 x 137) + 2[31 + (4x16)] = 411 + 2[31 + 64] = 601g/mol

Mass of Ba3(PO4)2 from the balanced equation = 1 x 601 = 601g

Summary:

From the balanced equation above,

411g of Ba reacted to produce 138g of Na and 601g of Ba3(PO4)2.

A. Determination of the mass of Na produced by reacting 10g of Ba.

From the balanced equation above,

411g of Ba reacted to produce 138g of Na.

Therefore, 10g of Ba will react to produce = (10 x 138)/411 = 3.36g of Na.

Therefore, 3.36g of Na is produced.

B. Determination of the mass of Ba3(PO4)2 produced by reacting 10g of Ba.

From the balanced equation above,

411g of Ba reacted to produce 601g of Ba3(PO4)2.

Therefore, 10g of Ba will react to produce = (10 x 601)/411 = 14.62g of Ba3(PO4)2.

Therefore, 14.62g of Ba3(PO4)2 is produced.

7 0

2 years ago

An example of a solid solution is copper true or false

garik1379 [7]

This is false, because copper is an element.
To be solution, it has to have at least 2 different substances. Solid solution of metals is often called alloy.

4 0

3 years ago