All categories

3 years ago

Pls help me brainliest, rattings etc its 2 questions and I am very confused! 8 pts!

Chemistry

2 answers:

xenn [34]3 years ago

8 0

Question 10 is the decomposition of water. The left side is 2 water molecules, while the right side is two hydrogen molecules and 2 oxygen molecules.

Question 11 consists of calculating the amounts of atoms on each side. Since the left side has 6 hydrogen atoms, the right side must as well. On the right side, hydrogen has a 2. So divide 6 by 2 to find the coefficient (3). You can confirm the answer by confirming the oxygen is the same on both sides (it is).

Serjik [45]3 years ago

6 0

Ouestion no 10 answer is first and 11 is 3

You might be interested in

How many grams are there in 3.4 x 10^24 atoms of He?

Lelechka [254]

Given :

Number of He atoms, $n = 3.4\times 10^{24}$ atoms.

To Find :

How many grams are their in given number of He atoms.

Solution :

We know, molecular mass of He is 4 g. It means that their are $6.022 \times 10^{23}$ atoms in 4 g of He.

Let, number of gram He in $3.4\times 10^{24}$ atoms is x , so :

$x = \dfrac{3.4\times 10^{24}}{6.022\times 10^{23}}\times 4\\\\x = $$22.58\ g$

Therefore, grams of He atoms is 22.58 g .

5 0

3 years ago

What element is this? How do you know?

postnew [5]

Atom is the most basic unit of matter. They are the general term used to describe pieces of matter. But a different kind of atom makes up an element. A combination of atom of different elements creates a molecule. For example, you have water; it has a chemical formula of H2O. If you separate H from O, you have two atoms. Two atoms for hydrogen and one atom for oxygen. However, they are of different elements. And when you combine them to form H2O, you create a molecule.

4 0

3 years ago

What is the theoretical yield of aspirin ( C 9 H 8 O 4 ), which has a molar mass of 180.15 g/mol, possible when reacting 3.03 g

pantera1 [17]

Answer:

The theoretical yield of aspirin is 3.95 grams

Explanation:

Step 1: Data given

Mass of salicylic acid = 3.03 grams

Volume of acetic anhydride = 3.61 mL

Density of acetic anhydride = 1.08 g/cm³

Step 2: The balanced equation

C4H6O3+C7H6O3→C9H8O4+C2H4O2

Step 3: Calculate moles salicylic acid

Moles salicylic acid = mass salicylic acid / molar mass salicylic acid

Moles salicylic acid = 3.03 grams /138.121 g/mol

Moles salicylic acid = 0.0219 moles

Step 4: Calculate mass acetic anhydride

Mass acetic anhydride = volume * density

Mass acetic anhydride = 3.61 mL * 1.08 g/mL

Mass acetic anhydride = 3.90 grams

Step 5: Calculate moles acetic anhydride

Moles acetic anhydride = 3.90 grams / 102.09 g/mol

Moles acetic anhydride = 0.0382 moles

Step 6: Calculate limiting reactant

For 1 mol salicylic acid we need 1 mol acetic anhydride to produce 1 mol aspirin

Salicylic acid is the limiting reactant. It will completely be consumed. (0.0219 moles). Acetic anhydride is in excess. There will react 0.0219 moles. There remain 0.0382 - 0.0219 =0.0163 moles

Step 7: Calculate moles aspirin

For 1 mol salicylic acid we need 1 mol acetic anhydride to produce 1 mol aspirin

For 0.0219 moles salicylic acid we'll have 0.0219 moles aspirin

Step 8: Calculate theoretical yield of aspirin

Mass of aspirin = moles aspirin *molar mass aspirin

Mass of aspirin = 0.0219 moles *180.15 g/mol

Mass of aspirin = 3.95 grams

The theoretical yield of aspirin is 3.95 grams

7 0

4 years ago

Both white phosphorus and red phosphorus are made up only of phosphorus atoms.Does this mean they are both pure substances? Coul

choli [55]

True, both of the red and white phosphorus is a pure substance.

Both red and white phosphorus is made of phosphor element but they have a different structure which causes them to have a different color. This phenomenon called allotropes when a chemical element has two or more different form.They are not compounds as they are only made of phosphorus. A compound should be made by at least two different elements.

4 0

3 years ago

The atom in a sample of an element must contain nuclei with the same number of?

slava [35]

Hey there!

Answer: Protons

The atom in a sample of an element must contain nuclei with the same number of protons. If the protons change in number, then the element will modify as well.

Thank you!

7 0

3 years ago