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3 years ago

Which of the following is an example of a pure substance? *

Chemistry

1 answer:

Natali [406]3 years ago

3 0

Answer:

Iron shavings

Explanation:

A substance that has a fixed chemical composition throughout and a mixture is when two or more substances are combined, but they are not combined chemically.

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How much heat energy is needed to raise the temperature of 59.7g of cadmium from 25°C to 100°C? The specific heat of cadmium is

labwork [276]

Using the Fundamental Equation of Calorimetry, we have:

$Q=mc\Delta T \\ Q=59.7.0.231.(100-25) \\ \boxed {Q=1034.3025J}$

If you notice any mistake with my english, please know me, because I am not native.

7 0

4 years ago

1. Which of the following particles are free to drift in metals?

kotegsom [21]

Answer:

electrons

Explanation:

metals do what is called metallic bond

8 0

3 years ago

Options:

Inessa [10]

Answer:

saturated fats

Explanation:

bcoz it is solid at room temperature and does not have double bonds between carbons

8 0

3 years ago

How many grams of Fe can be produced when 5.50 g of Fe2O3 reacts?

vichka [17]

Answer:

3,85 g of Fe

Explanation:

1- The first thing to do is calculate the molar mass of the Fe2O3 compound. With the help of a periodic table, the weights of the atoms are searched, and the sum is made:

Molar mass of Fe2O3 = (2 x mass of Fe) + (3 x mass of O) = 2 x 55.88 g + 3 x 15.99 g = 159.65 g / mol

Then, one mole of Fe2O3 has a mass of 159.65 grams.

2- Then, the relationship between the Fe2O3 that will react and the iron to be produced. With the previous calculation, we can say that with one mole of Fe2O3, two moles of Fe can be produced. Passing this relationship to the molar masses, it would be as follows:

1 mole of Fe2O3_____ 2 moles of Fe

159.65 g of Fe2O3_____ 111.76 g of Fe

3- Finally, the calculation of the mass that can be produced of Fe is made, starting from 5.50 g of Fe2O3

159.65 g of Fe2O3 _____ 111.76 g of Fe

5.50 g of Fe2O3 ______ X = 3.85 g of Fe

Calculation: 5.50 g x 111.76 g / 159.65 g = 3.85 g

The answer is that 3.85 g of Fe can be produced when 5.50 g of Fe2O3 react

7 0

3 years ago

A potassium bromide solution is 8.30% potassium bromide by mass and its density is 1.03 g/ml. what mass of potassium bromide is

pshichka [43]

Answer: The mass of potassium bromide present in 41.2 mL of solution will be 3.522 grams.

Explanation:

We are given that KBr is present in 8.3% KBr solution, which means that 8.3 grams of potassium bromide is present in 100 gram of the solution.

To calculate the volume of KBr, we use the formula:

$Density=\frac{Mass}{Volume}$

Mass of the solution = 100 grams

Density of KBr solution = 1.03g/mL

Volume of the solution = ? mL

Putting values in above equation, we get:

$1.03g/mL=\frac{100g}{Volume}\\\\Volume=97.08mL$

Now, to calculate the mass of KBr in 41.2mL of the solution, we use unitary method.

In 97.08 mL of solution, mass of KBr present is 8.3 grams.

So, 41.2 mL of solution will contain = $\frac{8.3g}{97.08mL}\times 41.2mL=3.522g$ of KBr.

Hence, the mass of potassium bromide present in 41.2 mL of solution will be 3.522 grams.

7 0

3 years ago