All categories

3 years ago

Look at the questions below and decide which is declarative.

1 answer:

3 0

Im not sure but here is some information to help A declarative question is a yes-no question that has the form of a declarative sentence but is spoken with rising intonation at the end. Declarative sentences are commonly used in informal speech to express surprise or ask for verification.

You might be interested in

a 68.4-g sample of potassium chloride was added to 200.0g of water at 20 degrees C. Is the solution saturated, unsaturated, or s

Thepotemich [5.8K]

Answer is: the solution is saturated.

Solubility of potassium chloride (KCl) on 20°C is 34.2 grams in 100 grams of water, so in 200 grams of water will dissolve two times more salt (68.4 g).

Saturated solution contains the maximum concentration of a solute dissolved in the solvent (usually water) and if extra solute is add to saturated solution, that solute will not dissolve.

The amount of solute that can be dissolved in a solvent depends of chemical composition, temperature and pressure.

7 0

3 years ago

Read 2 more answers

Niobium-91 has a half-life of 680 years. After 2,040 years, how much niobium-91 will remain from a 300.0-g sample? 3 g 18.75 g 3

Vadim26 [7]

Amount of Niobium-91 initially
= 300/91 =3.2967mol
2040 years = 3 ×680 = 3 half-lives
therefore, amount left = 0.4121mol
mass of Niobium-91 remaining = 0.4121 ×91 =37.5g

7 0

3 years ago

Read 2 more answers

In Ontario, some electricity comes from coal-burning generators. Coal is a natural form of carbon that has a large amount of sul

irinina [24]

Answer:

$C(s)+O_{2}(g) \rightarrow CO_{2}(g)$

$S(s)+O_{2}(g) \rightarrow SO_{2}(g)$

Sulphurdioxide

$SO_{2}(g) + H_{2}O(l) \rightarrow H_{2}SO_{3}(l)$

$SO_{2}(g) + \frac{1}{2}O_{2} \rightarrow SO_{3}(g)$

Incomplete combustion produce harmful gases.

Explanation:

Carbon reacts with atmospheric oxygen to form carbondioxide as well as sulphur dioxide.

The chemical equations are as follows.

$C(s)+O_{2}(g) \rightarrow CO_{2}(g)$

$S(s)+O_{2}(g) \rightarrow SO_{2}(g)$

Sulfur dioxide is very harmful to the environment to cause acid rains.

This harmful gas mix with rain water to form sulphuric acid.

The balanced chemical equation for the reaction that produces harmful environmental effects is as follows.

$SO_{2}(g) + H_{2}O(l) \rightarrow H_{2}SO_{3}(l)$

$SO_{2}(g) + \frac{1}{2}O_{2} \rightarrow SO_{3}(g)$

$SO_{3}(g) +H_{2}O(l) \rightarrow H_{2}SO_{4}(l)$

In the absence of proper amount of oxygen required for combustion, incomplete combustion will take place which will result in formation of more carbondioxide an other harmful gases.

4 0

3 years ago

Help with this question pleasee

kvv77 [185]

Solids. Example: when you hit a drum, it vibrates, then the sound travels through the air, to your ears.

8 0

3 years ago

Read 2 more answers

List three metal ions that commonly participate in biological redox chemistry, and give examples of how they participate.

Virty [35]

Dehydrogenation is catalyzed by Cu, Mo and Fe by changing their oxidation states.

5 0

3 years ago