Select all the correct answers.

Chemistry

2 answers:

swat324 years ago

8 0

Silver tarnishes and becomes black when exposed to oxygen:

Diesel fuel burns when it is heated:

Mashutka [201]4 years ago

7 0

Answer:

Silver tarnishes and becomes black when exposed to oxygen:

Diesel fuel burns when it is heated:

Explanation:

Chemical Changes are those changes in which the chemistry at molecular level is changed as the starting material is converted in to a new and different final material. This change takes place with the breaking of old bonds and forming of new bonds respectively.

Silver tarnishes and becomes black when exposed to oxygen:

This is a chemical change as Silver a white and lustrous starting material is being converted into a tarnish black final material. However, Silver doesn't readily react with oxygen at normal conditions. It readily react with Sulfur containing compounds in air and produces black compound as Ag₂S.

Diesel fuel burns when it is heated:

Diesel is a mixture of hydrocarbons ranging approximately from C₁₀H₂₀ to C₁₅H₂₈. When these hydrocarbons are burnt they produces a new materials i.e. CO₂ and H₂O.

C₁₀H₂₀ + 15 O₂ → 10 CO₂ + 10 H₂O

Hence, it is also a chemical reaction.

You might be interested in

A military jet cruising at an altitude of 12.0kmand speed of 1900./kmh burns fuel at the rate of 74.4/Lmin. How would you calcul

anygoal [31]

Answer: amount = 2466.95L

Explanation:

given that the speed is = 1900./kmh i.e. 1hr/900km

distance = 1050km

the fuel burns at a rate of 74.4 L/min

therefore the amount of fuel that the jet consumes on a 1050.km becomes;

total fuel used = time × fuel burning rate

where time = distance / speed

∴ total fuel used (consumed) = time × fuel burning rate

total fuel consumed = (1050km × 1hr/1900km) × (60min/ 1hr × 74.4L/1min)

total fuel consumed = 2466.95L

6 0

4 years ago

Draw a hemiacetal, an acetal, and an imine that can be formed from propanal (C3H6O). Circle those that form in basic solution an

Paul [167]

Answer:

They are all formed in acidic solution.

Explanation:

The diagram for hemiacetal, acetal and imine is shown in the diagram below and a star is placed on the three of them since they are all form in acidic solution.

From the diagram; reaction of methanol with propanal leads to formation of hemiacetal. From CH₃OH(methanol), one hydrogen attaches itself to the Oxygen double bond on the propanal to form a new hydroxyl group, the other methoxyl (-O-CH₃) from methanol attaches itself to other part of the propanal.

The further addition of methanol to Hemiacetal yields to Acetal.

Imines are formed by Mannich Reaction which is the reaction of propanal with amine group and which is followed by the dehydration with a Schiff base.