CHEMISTRY COLLEGE

Which of the following is an example of a compound? water - H2Ooxygen-O2
hydrogen - H2
helium - He

Answers

Answer 1
Answer:

Answer:

water

Explanation:

the other options are elements while water is 2 elements

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Consider the following reaction at equilibrium: NO2(g) + CO(g) = NO(g) + CO2(g) Suppose the volume of the system is decreased at constant temperature, what change will this cause in the system? A shift to produce more NO A shift to produce more CO A shift to produce more NO2 No shift will occur

I need help!! ASAP please..

Answers

Answer:

164 g

Explanation:

Lithium (Li) has a charge of +1, and oxygen has a charge of -2. Which is the chemical formula?

Answers

Considering the formation of a chemical formula, the chemical formula is Li₂O.

Ionic compounds

Cations (positivelycharged ions) and anions (negatively charged ions) combine to form ionic compounds, which must be electrically neutral. Therefore, the cations and anions must combine in such a way that the net charge contributed by the total number of cations exactly cancels the net charge contributed by the total number of anions.

Formation of a chemical formula

To form the chemical formula:

  • It is first necessary to place the chemical symbol of the element that is a cation, and then the negative part (anion).
  • Since the net charge of the compound formed must be zero (that is, add zero), when cations and anions with different charges are joined, it is necessary to cross them and place them as subscripts of the other element. In this way, balanced loads are obtained, that is, the algebraic sum is equal to zero.

Chemical formula in this case

Lithium (Li) has a charge of +1, and oxygen has a charge of -2. Taking into account the above, the chemical formula is Li₂O.

Answer:

Lithium formula=Li+

Oxygen formula=O2(2-)

Explanation:

Quick note: These kinds of formula are really easy to google. Next time, google the chemical name, include the charge and include "formula" and you should get the answer.

Identify the catalyst-containing systems below as homogeneous or heterogeneous. Catalysts (4 items) (Drag and drop into the appropriate area below) NO(g) for the oxidation of SO2(g) to SO3(g)KI(aq) for the decomposition of H2O2(aq)H2(g) bonded to a metal surfacePd(s) coating that converts noxious gas to less harmful gases

Answers

Answer:Homogeneous catalysts:NO(g), KI(aq.)

              Heterogeneous catalyst:H₂(g) bonded to a metal surface,Pd(s) Coating

Explanation:

Homogeneous catalysis is a catalysis reaction in which the reactants as well the catalyst catalyzing the reaction are in the same phase that is, the catalyst and reactants have same phase.

In the examples NO(g) which acts as a catalyst for the oxidation of SO₂(g) to SO₃(g) is in the same gaseous phase  as the reactant SO₂(g). So this is an example of homogeneous catalysis.

In the example KI(aq.) which acts as a catalyst for the decomposition of H₂O₂(aq.) is in the same aqueous phase as reactant H₂O₂(aq.). So this is an example of homogeneous catalysis.  

Hence NO(g) and KI(aq.) are homogeneous catalysts.

Heterogeneous catalysis is a catalysis reaction  in which the reactants and catalyst are in different phase . That is the catalyst and reactant do not have same phase.

In the examples H₂(g) bonded to a metal surface is an example of heterogeneous catalysis as the phase of H₂(g) and metal surface(s) are different hence this is an example of heterogeneous catalysis.

The Pd(s) acting as a catalyst for the conversion of  noxious gas to less harmful gas  is also an example of heterogeneous catalyst as the phase of Pd(s) and gases are different. Pd(s) is solid and the gases are gaseous in nature.

. Explain why, in the sample calculations, 0.1 g of the unknown produced a GREATER freezing point depression than~e same mass of naphthalene.

Answers

Answer

Naphthalene is a non electrolyte

If the unknown compound is an electrolyte it gives 2 or more ions in solution

( NaCl >> Na+ + Cl- => 2 ions

Ca(NO3)2 >> Ca2+ + 2 NO3- => 3 ions)

the f.p. lowering is directly proportional to the molal concentration of dissolved ions in the solution )

For naphthalene

delta T = 1.86 x m

for a salt that gives 2 ions

delta T = 1.86 x m x 2

hence the lowering in freezion point of unkown is greater then napthalene

Hich nuclide is most likely to undergo beta decay?which nuclide is most likely to undergo beta decay?co−52ar−35si−22mg−28

Answers

200
     Pt
 78
 is most likely to undergo beta decay.

During the process of beta decay the mass number of the parent nuclide becomes equal to the newly created nuclide. On the other hand, the atomic number of the newly created nuclei increases or decreases by one unit.

carbon dioxide at 25 degrees celsius and 101.3 kpa has a density of 1.799 kg/m^3 determine gas constant

Answers

Answer:

Explanation:

Temperature of gas in absolute scale T = 25 + 273 = 298 .

pressure of gas P = 1.013 x 10⁵ N / m²

density D = 1.799 kg / m³

= 1799 g / m³

From gas formula

PV / T = n R Where P is pressure , V is volume and T is absolute temperature , n is no of moles

P / T = n R / V

P / T = m R /M V where m is mass of gas and M is molecular weight .

m / V = D ( density )

P / T = DR/ M  

PM / DT = R

Putting the values

1.013 x 10⁵ x 44  /  (1799 x 298)

R = 8.314.09 J / K mole

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