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3 years ago

What does the law of conservation of matter state?

Chemistry

2 answers:

Sergio [31]3 years ago

8 0

The principle that in any closed system

11111nata11111 [884]3 years ago

6 0

Any system closed to the transfers of matter and energy means the mass of the system must remain constant over time. as system mass cannot change quantity if it is not added or removed

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What is the name of this hydrocarbon?

Phoenix [80]

Answer:

alkanes alkens alkenes and a bromatic hydrocarbons

5 0

2 years ago

Read 2 more answers

1 If it takes 67 mL of 0.15 M NaOH to neutralize 134 mL of an HCl solution, what is the concentration of the HCl? (5 points)

Neporo4naja [7]

Answer:

Q₁- The concentration of HCl = 0.075 N = 0.075 M.

Q₂- The concentration of KOH = 7.675 mN = 7.675 mM.

Q₃- The concentration of H₂SO₄ = 0.2115 N = 0.105 M.

Q₄- The equivalence point is the point at which the added titrant is chemically equivalent completely to the analyte in the sample whereas the endpoint is the point where the indicator changes its color.

Explanation:

Q₁: 

As acid neutralizes the base, the no. of gram equivalent of the acid is equal to that of the base.

The normality of the NaOH and HCl = Their molarity.

∵ (NV)NaOH = (NV)HCl

∴ N of HCl = (NV)NaOH / (V)HCl = (0.15 N)(67 mL) / (134 mL) = 0.075 N.

∴ The concentration of HCl = 0.075 N = 0.075 M.

Q₂:

As mentioned in Q1, the no. of gram equivalent of the acid is equal to that of the base at neutralization.

The normality of H₂SO₄ = Molarity of H₂SO₄ x 2 = 0.050 M x 2 = 0.1 N.

∵ (NV)H₂SO₄ = (NV)KOH

∴ N of KOH = (NV)H₂SO₄ / (V)KOH = (0.1 N)(27.4 mL) / (357 mL) = 7.675 x 10⁻³ N = 7.675 mN.

∴ The concentration of KOH = 7.675 mN = 7.675 mM.

Q₃:

As mentioned in Q1 and 2, the no. of gram equivalent of the acid is equal to that of the base at neutralization.

The normality of NaOH = Molarity of NaOH = 0.5 N.

∵ (NV)H₂SO₄ = (NV)NaOH

∴ N of H₂SO₄ = (NV)NaOH / (V)H₂SO₄ = (0.5 N)(55 mL) / (130 mL) = 0.2115 N.

∴ The concentration of H₂SO₄ = 0.2115 N = 0.105 M.

Q₄:

The equivalence point is the point at which the added titrant is chemically equivalent completely to the analyte in the sample whereas the endpoint is the point where the indicator changes its color.

The equivalence point in a titration is the point at which the added titrant is chemically equivalent completely to the analyte in the sample. It comes before the end point. At the equivalence point, the millimoles of acid are chemically equivalent to the millimoles of base.

End point is the point where the indicator changes its color. It is the point of completion of the reaction between two solutions.

The effectiveness of the titration is measure by the close matching between equivalent point and the end point. pH of the indicator should match the pH at the equivalence to get the same equivalent point as the end point.

4 0

3 years ago

If an electron gains energy what may happen to it

Illusion [34]

It could get bigger or it could have something a lot different to it than anything else

3 0

3 years ago

Compute the percentage of error to the nearest tenth in the student’s calculation if the actual specific heat value for aluminum

Artist 52 [7]

Complete Question:

1. A block of aluminum with a mass of 140 g is cooled from 98.4°C to 62.2°C with a release of 4817 J of heat. From these data, calculate the specific heat of aluminum.

a. Compute the percentage of error to the nearest tenth in the student's calculation if the actual specific heat value for aluminum is 0.9 J/g°C

Answer:

Percent error = 55.56 %

Explanation:

Given the following data;

Mass = 140 grams

Initial temperature = 62.2°C

Final temperature = 98.4°C

Quantity of heat = 4817 Joules.

To find the specific heat capacity;

Heat capacity is given by the formula;

$Q = mcdt$

Where;

Q represents the heat capacity or quantity of heat.
m represents the mass of an object.
c represents the specific heat capacity of water.
dt represents the change in temperature.

dt = T2- T1

dt = 98.4 - 62.2

dt = 36.2°C

Making c the subject of formula, we have;

$c = \frac {Q}{mdt}$

Substituting into the equation, we have;

$c = \frac {4817}{140*36.2}$

$c = \frac {4817}{5068}$

Specific heat capacity, = 0.95 J/g°C

b. To find the percentage error;

Given the following data;

Actual specific heat capacity = 0.9 J/g°C

Experimental specific heat capacity = 0.95 J/g°C

Percent error can be defined as a measure of the extent to which an experimental value differs from the theoretical value.

Mathematically, it is given by this expression;

$Percent \; error = \frac {experimental \;value - actual \; value}{ actual \;value} *100$

Substituting into the formula, we have;

$Percent \; error = \frac {0.95 - 0.9 }{ 0.9} *100$

$Percent \; error = \frac {0.5}{0.9} *100$

$Percent \; error = 0.5556 *100$

Percent error = 55.56 %

5 0

3 years ago

Why is the work done when a system expands against a constant external pressure assigned a negative sign?

Zina [86]

Formula of work done, W = - P (final volume - initial volume)

Here, W = work done

P = external pressure

External pressure is constant. In case of expansion final volume is greater than initial volume, therefore change in volume is positive.

W = negative ( positive )

W = negative

So, In case of expansion, the negative value of work indicates that the work is done by the system on the surrounding. Energy is released by system.

The sum of the forces of all of the molecules placing the wall divided by using the area of the wall is described to be the pressure. The pressure of a gasoline is then a measure of the common linear momentum of the moving molecules of a gas. The unit of pressure is pascal.

Learn more about work done here:- brainly.com/question/26040104

#SPJ4

5 0

2 years ago