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2 years ago

Explain how the heat and phase changes affects the environment? Give examples.(5-7 sentences)

1 answer:

7 0

Energy is required to change the phase of a substance, such as the energy to break the bonds between molecules in a block of ice so it may melt.
During a phase change energy my be added or subtracted from a system, but the temperature will not change. The temperature will change only when the phase change has completed. No temperature change occurs from heat transfer if ice melts and becomes liquid water (i.e., during a phase change). For example, consider water dripping from icicles melting on a roof warmed by the Sun. Conversely, water freezes in an ice tray cooled by lower-temperature surroundings. Energy is required to melt a solid because the cohesive bonds between the molecules in the solid must be broken apart so that the molecules can move around at comparable kinetic energies; thus, there is no rise in temperature.

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) Given the following balanced equation, determine the rate of reaction with respect to [O2]. If the rate of formation of O2is 7

Travka [436]

Answer:

Rate of the reaction is 0.2593 M/s

-0.5186 M/s is the rate of the loss of ozone.

Explanation:

The rate of the reaction is defined as change in any one of the concentration of reactant or product per unit time.

$2O_3\rightleftharpoons 3O_2$

Rate of formation of oxygen : $7.78\times 10^{-1} M/s$

Rate of the reaction(R) = $\frac{-1}{2}\frac{d[O_3]}{dt}=\frac{1}{3}\frac{d[O_2]}{dt}$

$R=\frac{1}{3}\frac{d[O_2]}{dt}$

Rate of formation of oxygen=3 × (R)

$7.78\times 10^{-1} M/s=3\times R$

Rate of the reaction(R): $0.2593 M/s$

Rate of the reaction is 0.2593 M/s

Rate of disappearance of the ozone:

$R=-\frac{1}{2}\frac{d[O_3]}{dt}$

$\frac{d[O_3]}{dt}=-2\times R=-2\times 0.2593\times M/s=-0.5186M/s$

-0.5186 M/s is the rate of the loss of ozone.

6 0

3 years ago

What the Purpose of seeds

k0ka [10]

Answer:

The purpose of all seed is reproduction and is to grow a new plant, thus propagating the species.

5 0

2 years ago

PLZ ANSWER QUICKLY! The electronegativity values of carbon, hydrogen, and nitrogen are compared in the table. Comparison of Elec

andriy [413]

Answer:

c. CH4 < NH3 because the NH bond is more polar than the CH bond.

Explanation:

Actually, the electronegativity difference between carbon and hydrogen is just about 0.4. This meager difference in electronegativity corresponds to a nonpolar bond between the two atoms.

However, the electronegativity difference between nitrogen and hydrogen is about 0.9. This larger electronegativity difference corresponds to the existence of a polar covalent bond between the two atoms.

Hence the N-H bond is significantly polar unlike the C-H bond. This implies that CH4 molecules are only held together by weak dispersion forces while NH3 molecules are held together by stronger dipole-dipole interactions and hydrogen bonds.

8 0

2 years ago

There are many minerals which contain silver. A 2.00 g sample of one of these, stephanite, is placed in water and all of its sil

Nata [24]

Answer:

68.3%

Explanation:

First, let us look at the equation of reaction involving silver and magnesium chloride:

2Ag + MgCl2 ----> 2AgCl + Mg

1 mole of MgCl2 is required to precipitate 2 moles of Ag completely from the solution. That is a ratio of 1 to 2.

Now, mole of MgCl2 used to precipitate all the Ag

= molarity x volume

= 2.19 M x 2.89/1000

= 0.0063291 mole

Since 1 mole of MgCl2 would always require 2 moles of Ag, 0.0063291 mole will therefore require:

0.0063291 x 2 = 0.0126 mole of Ag

This means that 0.0126 mole of Ag is present in stephanie.

Mass of silver in stephanie = mole x molar mass

= 0.0126 x 107.8682

= 1.365 g

Thus, 1.365 g of silver is present in 2.00 g sample of stephanie.

Mass percent of silver in stephanie = 1.365/2.00 x 100

= 68.25% = 68.3% to the correct number of significant figure.

4 0

3 years ago

Explain why a potassium atom would not bond with a calcium atom?

docker41 [41]

Answer:

Calcium atoms have smaller radii than potassium atoms since calcium atoms have a greater nuclear charge. Each calcium atom will be closer to the delocalized electrons. Thus, the bonds in calcium will be stronger than that in potassium.

Explanation:

6 0

2 years ago

Explain how the heat and phase changes affects the environment? Give examples.(5-7 sentences)​

Explain how the heat and phase changes affects the environment? Give examples.(5-7 sentences)