All categories

3 years ago

HELLP I NEEED HELP NOWW NO GUESSING FRFR

Chemistry

1 answer:

Ratling [72]3 years ago

5 0

It’s b . The magnesium will dissolve and the copper will be deposited

You might be interested in

in an experiment 3.425g of lead oxide was reduced to form 3.105g of lead the empirical formula of the lead oxide is?

Romashka-Z-Leto [24]

Answer:

Pb3O4

Explanation:

According to this question, 3.425g of lead oxide was reduced to form 3.105g of lead in an experiment. Since lead oxide contains both lead (Pb) and oxygen (O) element,

Mass of lead oxide = 3.425g

Mass of lead = 3.105g

Mass of oxygen = (3.425g - 3.105g) = 0.320g

Next, we convert each mass value to mole by dividing by respective molar mass

Pb = 3.105g ÷ 207.2 = 0.0149mol

O = 0.320g ÷ 16 = 0.02mol

Next, we divide each mole value by the smallest (0.0149)

Pb = 0.0149mol ÷ 0.0149mol = 1

O = 0.02mol ÷ 0.0149mol = 1.342

Multiply each ratio value by 3 to get:

Pb = 1 × 3 = 3

O = 1.342 × 3 = 4.026

The whole number ratio, approximately, of Pb and O is 3:4, hence, their empirical formula is Pb3O4.

4 0

3 years ago

Alex is 1.67 meters tall. His

nekit [7.7K]

Answer: A

Explanation:

1cm=.01 so it would be 167-34

5 0

3 years ago

Read 2 more answers

What type of a reaction takes place when atoms or molecules rearrange to form new substances

GREYUIT [131]

A chemical reaction happens when the atoms or molecules rearrange to form a new substance

6 0

4 years ago

Read 2 more answers

A student plans to use a density versus solution concentration standard curve to identify the sodium chloride concentration in a

Art [367]

Answer:

a. 0.50 g, 1.0 g, 1.5 g, 2.0 g, 2.5 g;

g. 0.1 g, 0.5 g, 1.0 g, 1.5 g, 2.0 g

Explanation:

The percent mass is defined as a ratio between the mass of a solute and mass of a solution:

$\omega = \frac{m_{solute}}{m_{solution}}\cdot 100\%$

Since solution only consists of a solute and solvent, express its mass as:

$m_{solution} = m_{solute} + m_{solvent}$

Then:

$\omega = \frac{m_{solute}}{m_{solution}}\cdot 100\%=\frac{m_{solute}}{m_{solute} + m_{solvent}}$

Firstly, solve for how much mass is required to prepare 3.0 %. Let's say, we have x g of the solute:

$0.03 = \frac{x}{30.0 + x}\therefore x = 0.03(30.0 + x)$

$x = 0.90 + 0.03x$

$0.97x = 0.90\therefore x = 0.93 g$

Similarly, solve for 6.0 %, let's say, we have x g of the solute again:

$0.06 = \frac{x}{30.0 + x}\therefore x = 0.06(30.0 + x)$

$x = 1.80 + 0.06x$

$0.94x = 1.80\therefore x = 1.91 g$

Hence, masses should be in a range of 0.93 g to 1.91 g.

7 0

4 years ago

1. Which combinations of substances resulted in a chemical change?(no answer choices)

Lunna [17]

All chemical reaction between substances results into a chemical change. When two substances just like HCL and NaOH reacts with each other, NaCl means Sodium Chloride salt is formed.

The phenomenon like change in color, change in temperature, release of gas etc when happens ,then it means chemical change has been occurred. e.g

HCl +NaOH ----> NaCl +H2O.

5 0

3 years ago

Read 2 more answers