The photo shows an animal called a water flea. Which level of organization is it an example of?

1)petroleum and natural gas are formed in the__________

ale4655 [162]

1. In the remains of organisms such as plants and algae.
2. Air, peace of mind know knowleged and water
3. The Carboniferous
4. Is a colorless , odorless gass that is very flammable.

6 0

3 years ago

Methanol, ethanol, and n−propanol are three common alcohols. When 1.00 g of each of these alcohols is burned in air, heat is lib

KengaRu [80]

Answer:

For methanol: Heat of combustion = -22.6 kJ / 0.0312 moles = -724.3590 kJ/mol (negative sign signifies release of heat)

For ethanol: Heat of combustion = -29.7 kJ / 0.0217 moles = -1368.6636 kJ/mol (negative sign signifies release of heat)

For propanol: Heat of combustion = -33.4 kJ / 0.0166 moles = -2012.0482 kJ/mol (negative sign signifies release of heat)

Explanation:

Given:

Mass of Methanol = 1.0 g

Mass of ethanol = 1.00 g

Mass of n-propanol = 1.00 g

For methanol:

2 CH₃OH + 3 O₂ ----> 2 CO₂ + 4 H₂O, ∆H₀ = -22.6 kJ/g (negative sign signifies release of heat)

1 g of methanol on combustion gives 22.6 kJ of energy

Calculation of moles of methanol:

$moles=\frac{Mass(m)}{Molar\ mass (M)}$

Molar mass of methanol = 32.04 g/mol

Thus moles of methanol = 1 g/ (32.04 g/mol) = 0.0312 moles

Hence energy in kJ/mol:

Heat of combustion = -22.6 kJ / 0.0312 moles = -724.3590 kJ/mol (negative sign signifies release of heat)

For ethanol:

C₂H₅OH + 3 O₂ ----> 2 CO₂ + 3 H₂O, ∆H₀ = -29.7 kJ/g (negative sign signifies release of heat)

1 g of ethanol on combustion gives 29.7 kJ of energy

Calculation of moles of ethanol:

$moles=\frac{Mass(m)}{Molar\ mass (M)}$

Molar mass of ethanol = 46.07 g/mol

Thus moles of ethanol = 1 g/ (46.07 g/mol) = 0.0217 moles

Hence energy in kJ/mol:

Heat of combustion = -29.7 kJ / 0.0217 moles = -1368.6636 kJ/mol (negative sign signifies release of heat)

For propanol:

2 C₃H₇OH + 9 O₂ ----> 6 CO₂ + 8 H₂O, ∆H₀ = -33.4 kJ/g , (negative sign signifies release of heat)

1 g of methanol on combustion gives 33.4 kJ of energy

Calculation of moles of methanol:

$moles=\frac{Mass(m)}{Molar\ mass (M)}$

Molar mass of methanol = 60.09 g/mol

Thus moles of methanol = 1 g/ (60.09 g/mol) = 0.0166 moles

Hence energy in kJ/mol:

Heat of combustion = -33.4 kJ / 0.0166 moles = -2012.0482 kJ/mol (negative sign signifies release of heat)

5 0

3 years ago

An interaction between atoms that holds them together by reducing the potential energy of their electrons

Lemur [1.5K]

Answer:

Chemical bond

Explanation:

Chemical bond is refer to as the interaction existing between two or more atoms, ions or molecules that holds them together by decreasing the potential energy of their electrons. Chemical bond leads to the formation of chemical compounds. Chemical bond may occur as a result of the electrostatic force of attraction that exists between oppositely charged ions such as those in ionic bonds or when electrons are shared such as those in covalent bonds.

6 0

3 years ago

What are properties of carbon

nirvana33 [79]

The physical and chemical properties of carbon depend on the crystalline structure of the element. Its density fluctuates from 2.25 g/cm³ (1.30 ounces/in³) for graphite and 3.51 g/cm³ (2.03 ounces/in³) for diamond. The melting point of graphite is 3500ºC (6332ºF) and the extrapolated boiling point is 4830ºC (8726ºF).

6 0

3 years ago

In an experiment, a compound was determined to contain 68.94% oxygen and 31.06% of an unknown element by weight. The molecular w

monitta

Answer is: the compound is B₂O₃.

ω(O) = 68.94% ÷ 100%.

ω(O) = 0.6894; percentage of oxygen in the compound.

ω(X) = 31.06% ÷ 100%.

ω(X) = 0.3106; percentage of unknown element in the compound.

If we take 69.7 grams of the compound:

M(compound) = 69.7 g/mol.

n(compound) = 69.7 g ÷ 69.7 g/mol.

n(compound) = 1 mol.

n(O) = (69.7 g · 0.6894) ÷ 16 g/mol.

n(O) = 3 mol.

M(compound) = n(O) · M(O) + n(X) · M(X).

n(X) = 1 mol ⇒ M(X) = 21.7 g/mol; there is no element with this molecular weight.

n(X) = 2 mol ⇒ M(X) = 10.85 g/mol; this element is boron (B).

8 0

3 years ago