Subjective questions

Which types of reactions would result in the formation of precipitate?

IRINA_888 [86]

Answer:

Double Displacement Reaction

Explanation:

A double displacement reaction is a type of chemical reaction in which the reactant ions exchange places to form new products. Usually, a double displacement reaction results in precipitate formation.

8 0

3 years ago

A 1.24g sample of a hydrocarbon, when completely burned in an excess of O2 yields 4.04g Co2 and 1.24g H20. Draw plausible struct

arsen [322]

Answer:

Plausible structure has been given below

Explanation:

Molar mass of $CO_{2}$ is 44 g/mol and molar mass of $H_{2}O$ is 18 g/mol
Number of mole = (mass/molar mass)

4.04 g of $CO_{2}$ = $\frac{4.04}{44}moles$ $CO_{2}$ = 0.0918 moles of $CO_{2}$

1 mol of $CO_{2}$ contains 1 mol of C atom

So, 0.0918 moles of $CO_{2}$ contains 0.0918 moles of C atom

1.24 g of $H_{2}O$ = $\frac{1.24}{18}moles$ $H_{2}O$ = 0.0689 moles of $H_{2}O$

1 mol of $H_{2}O$ contain 2 moles of H atom

So, 0.0689 moles of $H_{2}O$ contain $(2\times 0.0689)moles$ of $H_{2}O$ or 0.138 moles of $H_{2}O$

Moles of C : moles of H = 0.0918 : 0.138 = 2 : 3

Empirical formula of hydrocarbon is $C_{2}H_{3}$

So, molecular formula of one of it's analog is $C_{4}H_{6}$

Plausible structure of $C_{4}H_{6}$ has been given below.

4 0

3 years ago

Quis critérios foram usadps por dobereiner em sua tentava de organiza os elementos químicos?

anyanavicka [17]

Döbereiner grouped the known elements into triads (sets of three) so that

• The atomic mass of the middle element was approximately the average of the other two

• The chemical properties of the middle element were between those of the other two

• The physical properties of the middle element were between those of the other two

One example of a triad is Li – Na – K.

(a) Atomic mass of Na = 23.0 u

Average atomic mass of Li and K = (6.9 u + 39.1 u)/2 = 46.0 u/2 = 23.0 u

(b) Li reacts slowly with water. Na reacts rapidly. Potassium reacts violently.

(c) Melting point of Na = 371 °C.

Average melting point of Li and K = (454 °C + 330 °C)/2 = 784 °C/2

= 392 °C

8 0

3 years ago

A Flame test is an example of chemistry property. What evidence can you use to back your statement up?

Lena [83]

The flame test is a qualitative test used in chemistry to help determine the identity or possible identity of a metal or metalloid ion found in an ionic compound. If the compound is placed in the flame of a gas burner, there may be a characteristic color given off that is visible to the naked eye. And for the proof. The flame test provided evidence that specific atoms are present in compounds by the color of the flame. The metal atoms are what is responsible for the colors during the flame test. The color of the flame will be yellow-orange because Sodium (Na) is present in all the compounds that have a yellow-orange flame. Hope this helps! Mark brainly please!

7 0

3 years ago

Why is Jon Dalton’s discovery important to science? Help please

Veronika [31]

Answer:

Dalton expressed his assumption in A Modern Model of Chemical Theory that atoms of various elements should be uniformly differentiated, based on their differing atomic weights. In doing so, he became the first scientist to explain atom behavior as regards weight measurement.

Explanation:

8 0

3 years ago