All categories

3 years ago

Is pencil lead a heterogeneous or homogeneous mixture?

1 answer:

7 0

Is a pencil a mixture?

Yes, A pencil is a mixture because it can be separated. A mixture is a mix of substances that can be unmixed - like some cereal, the actual cereal can be taken out of the mix to become independent.
It's heterogeneous

You might be interested in

5. A hollow glass sphere has a volume of 350 mL and

Rina8888 [55]

Explanation:

Given that,

Volume of a hallow glass sphere is 350 mL

Specific gravity is 1.252

We need to find the weight of the sphere. The ratio of density of substance to the density of water is called specific gravity.

The density of water is 1 g/mL

$\text{specific gravity}=\dfrac{\text{density of substance}}{\text{density of water}}\\\\SG=\dfrac{m}{V\times \rho_w}\\\\m=SG\times V\times \rho_w\\\\m=1.252\times 350\ mL\times 1\ g/mL\\\\m=438.2\ \text{grams}$

We know that,

1 pound = 453.592 grams

So,

m = 0.97 lbs

So, the weight of the sphere is 0.97 lbs or 0.97 pounds.

5 0

4 years ago

The valence electrons are the number of electrons in an outer shell of an atom that can participate in forming chemical bonds wi

Agata [3.3K]

The answer is true

5 0

3 years ago

Write an equation for the reaction of the Tollens reagent<br> withheptanal?

dangina [55]

Answer:

$CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 CHO + 2[Ag(NH_3)_2]+ 3 H_2 O$ = $CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 COOH +2Ag + 4NH_3$

Explanation:

Tollens test is carried out to perceive difference between aldehydes and ketones on the basis of their capability to oxidized easily.

when Tollens react with aldehyde (heptanal) , a silver mirror is form on inner side of container.

The reaction between tollens and heptanal is given as

$CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 CHO + 2[Ag(NH_3)_2]+ 3 H_2 O$ = $CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 COOH +2Ag + 4NH_3$

8 0

4 years ago

Read the following statement:

shepuryov [24]

The last one should be right

6 0

3 years ago

2 2. The energy stored in a substance that can be released when the substance reacts. A. Mechanical Energy B. Thermal Energy C.

vichka [17]

Answer:

C. Chemical Energy

Explanation:

The energy that stored in the substance or in compounds is called chemical energy which released when the substance reacts.

A substance is made up of atoms and molecules and chemical energy is present in those atoms or molecules. When a chemical reaction takes place, these energy released from atoms and molecules.

Chemical energy can be released in the form of thermal energy (heat) and mechanical energy (working ability).

Hence, the correct answer is "C. Chemical Energy".

4 0

3 years ago