Different substances are made from different ____________ which interact with water in different ways.

What is the percent composition of CuO if a sample of CuO with a mass of 62.5 g contains 12.5 g of oxygen (O) and 50 g of Cu

Arlecino [84]

Percent (%) Composition of CuO

Cu = 1 x 50g - Multiply by one as there is one Cu

O = 1 x 12.5g - Multiply by one as there is one O

CuO = 62.5g

% for Cu = 50g over 62.5 multiplied by 100 = 80%

% for O = 12.5g over 62.5 multiplied by 100 = 20%

Final Answer :

<em>Percent (%) Composition of CuO = </em>80% (Cu) & 20% (O)

7 0

3 years ago

Which characteristic do valence electrons indicate about reactions between atoms?

Setler [38]

Bond number

The characteristic of reactions that depends on valence electrons is the bond type.

In chemistry, a chemical bond could be;

Ionic

Covalent

The type of bond formed depends on the number of valence electrons present. When there are few valence electrons on an atom, it mostly forms ionic bonds.

When there are more electrons on an atoms, it mostly forms covalent bonds and the electrons between the atoms are shared.

6 0

3 years ago

How to balance the chemical equation: <br> CO2+H2O-->C6H12O6

Andru [333]

Answer:

6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂

Explanation:

The given reaction represent the formation of glucose so it is photosynthesis reaction.

Photosynthesis:

It is the process in which in the presence of sun light and chlorophyll by using carbon dioxide and water plants produce the oxygen and glucose.

Carbon dioxide + water + energy → glucose + oxygen

water is supplied through the roots, carbon dioxide collected through stomata and sun light is capture by chloroplast.

Chemical equation:

6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂

it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen.

4 0

4 years ago

Question 19 of 26

Alona [7]

Answer:

3Mg(NO3)2(aq)+2Na3PO4(aq)⇒Mg3(PO4)2(s)+6NaNO3(aq)

Explanation:

4 0

3 years ago

1 mol super cooled liquid water transformed to solid ice at -10 oC under 1 atm pressure.

Arada [10]

Answer:

Explanation:

Given that:

number of moles of super cooled liquid water = 1

Melting enthalpy of ice = 6020 J/mol

Freezing point =0 °C = (0 + 273 K)= 273 K

The decrease in entropy of the system during freezing for 1 mol (i.e during transformation from liquid water to solid ice ) = - 6020 J/mol × 1 mol /273 K = -22.051 J/K

Entropy change during further cooling from 0 °C (273 K) to -10 °C (263 K)

$\Delta \ S = \int\limits^{T_2}_{T_1}\dfrac{nC_p(s)dT}{T}$

$\Delta \ S = {nC_p(s)In \dfrac{T_2}{T_1}$

$\Delta \ S = {(1*37.7)In \dfrac{263}{273}$

Δ S = -1.4 J/K

Total entropy change of the system = - 22.05 J/K - 1.4 J/K = - 23.45 J/K

Entropy change of universe = entropy change of the system+ entropy change of the surrounding

According to the second law of thermodynamics

Entropy change of universe >0

SO,

Entropy change of the system + entropy change in the surrounding > 0

Entropy change in the surrounding > - entropy change of the system

Entropy change in the surrounding > - (- 23.53 J/K)

Entropy change in the surrounding > 23.53 J/K

b) Make some comments on entropy changes from the obtained data.

From the data obtained; we will realize that the entropy of the system decreases as cooling takes place when water is be convert to ice , randomness of these molecules reduces and as cooling proceeds , hence, entropy reduces more as well and the liberated heat will go into the surrounding due to this entropy of the surrounding increasing.

4 0

3 years ago