Calculate the mass in grams of each sample. 4.68×1020 H2O2 molecules

(Timed) What part of an atom involved in a chemical reaction?

tino4ka555 [31]

D.electron
The part of the atom involved in a chemical reaction is the electron cloud. The electron cloud is the part of the atom surrounding the nucleus.

4 0

3 years ago

For many purposes we can treat ammonia (NH) as an ideal gas at temperatures above its boiling point of -33.C. Suppose the temper

levacccp [35]

Answer:

In homeothermic (“warm-blooded”) animals, body temperature is carefully

regulated. The hypothalamus, located in the brain, acts as the master ther-

mostat to keep body temperature constant to within a fraction of a degree

Celsius in a healthy animal. If the body temperature starts to deviate much

from the desired constant level, the hypothalamus causes changes in blood

flow and initiates other processes, such as shivering or perspiration, to bring

the temperature back to normal. What evolutionary advantage does a con-

stant body temperature give the homeotherms (e.g., birds and mammals)

over the poikilotherms (e.g., reptiles and insects), whose body temperatures

are not kept constant? What are the disadvantages?

Explanation: Basic chemical understanding as revealed upwards

6 0

3 years ago

How many atoms are in each compound ?

noname [10]

Compounds are made of two or more atoms of different elements, such as water (H2O) and methane (CH4). Atoms are not drawn to scale. Molecules of compounds have atoms of two or more different elements.

7 0

3 years ago

Suppose a salt and a glucose solution are separated by a membrane that is permeable to water but not to the solutes. the nacl so

stira [4]

1)

m(NaCl) = 1.95 g
V(H2O) = 250mL
M(NaCl) = 58.5 g/mole

Since waters density value is 1g/mL, it can be assumed that volume and mass of water are same values:

V(H2O) = 250ml = 250g = 0.25 kg

molality of NaCl:

n(NaCl)=m/M=1.95/58.5= 0.033 mole

molality b(NaCl)=n(NaCl) / V (H2O)= 0.033/0.25 = 0.132 mol/kg

milimolality of NaOH = 0.132/0,001 = 132 mmole/kg

milliosmolality of NaOH = milimolality x N of ions formed in dissociation

Since NaCl dissociates into 2 ions in solution:

milliosmolality of NaOH = 132 x 2 = 264 osmoles/kg

2)

m(gl) = 9 g
V(H2O) = 250mL
M(NaCl) = 180 g/mole

Since waters density value is 1g/mL, it can be assumed that volume and mass of water are same values:

V(H2O) = 250ml = 250g = 0.25 kg

molality of glucose:

n(gl)=m/M=9/180= 0.05 mole

molality b(gl)=n(gl) / V (H2O)= 0.05/0.25 = 0.2 mol/kg

milimolality of glucose = 0.132/0,001 = 200 mmole/kg

milliosmolality of glucose = milimolality x N of ions formed in dissociation

Since glucose does not dissociate, milimolality and milliosmolality are same:

milliosmolality of glucose = 200 osmoles/kg

3)

The osmosis represents the diffusion of solvent molecules through a semi-permeable membrane that allows passage solvent molecules but does not to the dissolved substance molecule. The osmosis occurs when the concentrations of the solution on both sides of the membrane are different. Since the semi-permeable membrane only permeates the solvent molecules, but not the particles of the dissolved substance, it occurs the solvent diffusion through the membrane, i.e. the solvent molecules pass through the membrane to equalize the concentration on both sides of the membrane. Solvents molecules move from the middle with a lower concentration in the middle with a higher concentration of dissolved substances.

In our case, osmosis will occur because the concentration of NaCl solution and the concentration of glucose solution do not have same values. Osmosis will occur in the direction of glucose solution because it has a lower concentration.

3 0

4 years ago

What is the [OH-] in a solution with a pol of 7.86?

yulyashka [42]

Answer:

pH of 7.86, then the [OH-] is equal to 10^(14-7.86) = 10^6.14 M

Explanation:

3 0

3 years ago