Which description best matches Democritus idea of the atom?

Should the density of a metal depend on its volume?

jekas [21]

Answer:

Density is the ratio of the mass of an object to its volume. Density is an intensive property, meaning that it does not depend on the amount of material present in the sample. ... Since a cubic centimeter is equal to a milliliter, density units can also be expressed as g/mL.

Explanation:

6 0

3 years ago

A tank contains 90 kg of salt and 2000 L of water. Pure water enters a tank at the rate 6 L/min. The solution is mixed and drain

sashaice [31]

Answer:

a) 90 kg

b) 68.4 kg

c) 0 kg/L

Explanation:

Mass balance:

$-w=\frac{dm}{dt}$

w is the mass flow

m is the mass of salt

$-v*C=\frac{dm}{dt}$

v is the volume flow

C is the concentration

$C=\frac{m}{V+(6-3)*L/min*t}$

$-v*\frac{m}{V+(6-3)*L/min*t}=\frac{dm}{dt}$

$-3*L/min*\frac{m}{2000L+(3)*L/min*t}=\frac{dm}{dt}$

$-3*L/min*\frac{dt}{2000L+(3)*L/min*t}=\frac{dm}{m}$

$-3*L/min*\int_{0}^{t}\frac{dt}{2000L+(3)*L/min*t}=\int_{90kg}^{m}\frac{dm}{m}$

$-[ln(2000L+3*L/min*t)-ln(2000L)]=ln(m)-ln(90kg)$

$-ln[(2000L+3*L/min*t)/2000L]=ln(m/90kg)$

$m=90kg*[2000L/(2000L+3*L/min*t)]$

a) Initially: t=0

$m=90kg*[2000L/(2000L+3*L/min*0)]=90kg$

b) t=210 min (3.5 hr)

$m=90kg*[2000L/(2000L+3*L/min*210min)]=68.4kg$

c) If time trends to infinity the division trends to 0 and, therefore, m trends to 0. So, the concentration at infinit time is 0 kg/L.

6 0

3 years ago

Why does surface area of a reactant influence the rate of the reaction?

telo118 [61]

because it can influence how frequently and sufficiently the particles collide depending on the space it has to do so, for example a large surface area would be have a slower rate of reaction and a lower temperature. (the rate of reaction in terms of concentration, it is diffused from high to low)

7 0

3 years ago

Why must the spot applied to a TLC plate be above the level of the developing solvent? What problem will ensue if the level of t

algol13

Answer:

See explanation

Explanation:

If the spot in TLC is below the solvent front, it will be observed that the spot, instead of being separated by the solvent as expected, will just dissolve away in the solvent and zero actual separation of the mixture is achieved.

If the solute is dissolved away instead of being separated by the solvent, then the experiment fails because no actual separation of the mixture is achieved.

Hence, in TLC, the spot must be applied above the solvent front so that the capillary movement of the solvent through the plate can lead to the eventual separation of the components of the mixture since the various components of the mixture will travel at different speeds through the plate.

Also, if the solvent is above the spot, the solvent may evaporate selectively from the points above the spot while separation is ongoing.

6 0

3 years ago

Using this equation, m1v2=m2v2 , calculate the diluted molarity of 100 mL of a 0.5 M solution when 50 mL of

geniusboy [140]

The molarity of the diluted solution is 0.33 M

From the question given above, the following data were obtained:

Molarity of stock solution (M₁) = 0. 5 M

Volume of stock solution (V₁) = 100 mL

Volume of diluted solution (V₂) = 100 + 50 = 150 mL

<h3>Molarity of diluted solution (M₂) =? </h3>

The molarity of the diluted solution can be obtained by using the dilution formula as illustrated below:

0.5 × 100 = M₂ × 150

50 = M₂ × 150

Divide both side by 150

M₂ = 50 / 150

Therefore, the molarity of the diluted solution is 0.33 M

Learn more: brainly.com/question/24625656

8 0

3 years ago