Which of these statements about the conservation of mass is not correct?

How can you tell that a chemical change has occurred?

Alik [6]

A. The products of the change are different from the starting

substances.

Explanation:

Whenever there is a physical change it may just affect the phase change but the properties remains the same. Whenever there is an occurrence of a chemical change, it was indicated by some of these things such as,

The products are exactly different from the products.

Chemical properties of these reactants are entirely different from that of the products.

Chemical composition as well as the physical properties of the reactants and the products will change

5 0

3 years ago

When elemental boron, B, is burned in oxygen gas, the product is diboron trioxide. If the diboron trioxide is then reacted with

zalisa [80]

Answer: The chemical equation is written below.

Explanation:

Every balanced chemical equation follows law of conservation of mass.

This law states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form. This also means that total number of individual atoms on reactant side must be equal to the total number of individual atoms on the product side.

The chemical equation for the reaction of elemental boron and oxygen gas follows:

$4B+3O_2\rightarrow 2B_2O_3$

By Stoichiometry of the reaction:

4 moles of elemental boron reacts with 3 moles of oxygen gas to produce 2 moles of diboron trioxide.

The chemical equation for the reaction of diboron trioxide and water follows:

$B_2O_3+3H_2O\rightarrow 2H_3BO_3$

By Stoichiometry of the reaction:

1 mole of diboron trixoide reacts with 3 moles of water to produce 2 moles of boric acid.

Hence, the chemical equations are written above.

3 0

3 years ago

A chemical reaction that has a positive δg is correctly described as

Charra [1.4K]

Answer:

Endergonic reaction or nonspontaneous reaction.

Explanation:

Gibbs free energy is a state function that determines the spontaneity or feasibility of the given reversible chemical reaction, at fixed pressure and temperature. It is given by the equation:

ΔG = ΔH - TΔS

Here, ΔG - change in Gibbs free energy

ΔH- The change in enthalpy of reaction

ΔS - The change in entropy

T- Temperature

When the change in the Gibbs free energy for a given reaction is positive (ΔG > 0), then that chemical reaction is known as an endergonic reaction or nonspontaneous reaction.

4 0

3 years ago

Nitrogen gas is being withdrawn at the rate of 4.5 g/s from a 0.15-m3 cylinder, initially containing the gas at a pressure of 10

faust18 [17]

Answer:

Final temperature = 152.57K,

Pressure = 0.6907 bar.

dT/dt = - 1,151 K/s.

Explanation:

The first thing to do here is to write out the equation for mass balance as given below:

dN/dt = N -------------------------------------------------------------------------------------------(1).

N = P/T, then, substitute the values given in the question into:

d[p/T]/ dt = [- 4.5/28 × 8.314]/0.15 = - 8.9 × 10⁻⁵ bar/K.s.

Thus, there is the need to integrate, Integrate [p/T]f = 10/320 - 8.9 × 10⁻⁵ bar/K.s. ------------------------------------(2).

NB; fT = final temperature, fP = final pressure and iT = initial temperature.

Also, [ fT]³⁰/₈.₃₁₄/ [fP] = [iT]³⁰/₈.₃₁₄/ Pi] = [ 320]³⁰/₈.₃₁₄/ 10.

Therefore, [fT]³⁰/₈.₃₁₄ = 109.52 × 10⁶.

Final temperature= [fP]³⁰/₈.₃₁₄ × 169.05.

Note that fP/ [fP]³⁰/₈.₃₁₄ × 169.05 = 10/320 - 8.9 × 10⁻⁵.

Therefore, [fP]¹ ⁻ ³⁰/₈.₃₁₄ = 0.7651.

Hence, Final temperature = 152.57K,

Pressure = 0.6907 bar

dT/ dt = N[RT]² / Cv . PV.

R = 30 - 8.314 = 21.86 J/mol K.

Then, the rate of change of the gas temperature at this time = dT/dt = - 1,151 K/s.

4 0

3 years ago

What is equavlent to 14,000 mm^3

aleksklad [387]

Answer:

1.4 * 10∧4

Brainliest pls

7 0

4 years ago