All categories

3 years ago

What is a chemical change?

2 answers:

8 0

Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions

egoroff_w [7]3 years ago

7 0

Chemical change accurs when a substance changes form like liquid to solid.

You might be interested in

Can someone show their work on how to do this: Calculate the number of moles of Al2O3 present in 23.87g. (Molar mass of Al2O3= 1

vodomira [7]

Answer:

0.234 moles

Explanation:

moles of Al2O3 = mass / molar mass

moles of Al2O3 = 23.87g / 102.0g/mol

moles of Al2O3 = 0.234 moles (to three significant figures)

6 0

3 years ago

There are 342 g of sucrose in 1.00 mol of sucrose. What is the molar concentration (molarity) of a solution containing 171 g suc

andrezito [222]

Given the values above, in order to know the molar concentration or the molarity of a solution containing 171 g of sucrose in 1.25L solution, here is the solution that you should follow: So,
MM = 342 (g/mol)
171 (g) / 342(g/mol) = x mol of sucrose
<span>x moles of sucrose/ 1.25 L = Molarity of solution
</span>Hope this is the answer that you are looking for.

6 0

3 years ago

If 12.85 g of chromium metal is reacted with 10.72 g of phosphoric acid, then what is the maximum mass in grams of chromium(III)

RUDIKE [14]

<h3>Answer:</h3>

16.02 g

<h3>Explanation:</h3>

<u>We are given;</u>

Mass of chromium as 12.85 g
Mass of phosphoric acid as 10.72 g

We are require to calculate the maximum mass of chromium (III) phosphate that can be produced.

The equation for the reaction is;

2Cr(s) + 2H₃PO₄(aq) → 2CrPO₄(s) + 3H₂(g)

<h3>Step 1: Determining the number of moles of Chromium and phosphoric acid</h3>

Moles = Mass ÷ Molar mass

Molar mass of chromium = 52.0 g/mol

Moles of Chromium = 12.85 g ÷ 52.0 g/mol

= 0.247 moles

Molar mass of phosphoric acid = 97.994 g/mol

Moles of phosphoric acid = 10.72 g ÷ 97.994 g/mol

= 0.109 moles

<h3>Step 2: Determine the rate limiting reactant </h3>

From the equation, 2 moles of chromium reacts with 2 moles of phosphoric acid.
Therefore, 0.247 moles of Chromium will require 0.247 moles of phosphoric acid, but we only have 0.109 moles.

This means chromium is in excess and phosphoric acid is the rate limiting reagent.

<h3>Step 3: Moles of Chromium(III) phosphate</h3>

From the equation, 2 moles of phosphoric acid reacts to yield 2 moles of chromium (III) phosphate.
Therefore, Moles of Chromium (III) phosphate = Moles of phosphoric acid

Hence; moles of CrPO₄ = 0.109 moles

<h3>Step 4: Maximum mass of CrPO₄ that can be produced</h3>

We know that, mass = Moles × Molar mass

Molar mass of CrPO₄ = 146.97 g/mol

Thus,

Mass of CrPO₄ = 0.109 moles × 146.97 g/mol

= 16.02 g

Thus, the maximum mass of CrPO₄ that can be produced is 16.02 g

7 0

4 years ago

Which of the following best describes the formation of plasma? (2 points)

Komok [63]

I agree with top guy C. and C makes most sense and sorry if I am wrong

6 0

3 years ago

Air containing 0.04% carbon dioxide is pumped into a room whose volume is 6000 ft3. The air is pumped in at a rate of 2000 ft3/m

koban [17]

Here is the full question:

Air containing 0.04% carbon dioxide is pumped into a room whose volume is 6000 ft3. The air is pumped in at a rate of 2000 ft3/min, and the circulated air is then pumped out at the same rate. If there is an initial concentration of 0.2% carbon dioxide, determine the subsequent amount in the room at any time.

What is the concentration at 10 minutes? (Round your answer to three decimal places.

Answer:

0.046 %

Explanation:

The rate-in;

$R_{in}$ $= \frac{0.04}{100}*2000$