All categories

3 years ago

What is the first law of thermodynamics also known as?

Chemistry

1 answer:

andrey2020 [161]3 years ago

3 0

Answer:

The answer is B) The law of conservation of energy.

Explanation:

This is the answer because energy cannot be created or be destroyed in a isolated system. The second law as well states that the entropy of any isolated system always increases.

You might be interested in

A solution of cough syrup contains 5.00% active ingredient by volume. If the total volume of the bottle is 44.0 mL , how many mi

Lelechka [254]

2.2 mL is how many mililiters of active ingredient

3 0

3 years ago

What element from the "Periodic Table" is named after an "Austrian Scientist"??

soldier1979 [14.2K]

Answer:

Should be either mendele or fermium

maybe lawrencium not sure but I think it’s lawrencium! Sorry if wrong heh

Explanation: really trying to help! If it’s wrong super sorry!!!

3 0

3 years ago

Ketones undergo a reduction when treated with sodium borohydride, NaBH4. The product of the above reaction has the following spe

Anna71 [15]

Answer:

The product is cyclohexanol

Explanation:

Firstly,

A ketone undergo a borohydride reduction reaction to form an alcohol as below,

R-CO-R' ⇒ R-CO(OH)-R'

IR Spectrum confirms that alcohol group is existed with the peak at 3400 cm⁻¹
From 1H-NMR, the product has 10 hydrogen atoms, the MS suggest that the formula is C₅H₁₀O (M = 86). With this formula, the alcohol is monosaturated. Since, the substance already underwent reduction reaction, the only way to suggest a monosaturated compound is a cyclic alcohol. So the compound is cyclopentanol.
Check with other spectroscopic properties,

3 signals of 13C NMR confirms the structure is symmetrical, δ 24.2, (-CH₂-CH₂-CH(CH₂-)-OH), δ 35.5 (-CH₂-CH₂-CH(CH₂-)-OH), δ 73.3 (-CH₂-CH₂-CH(CH₂-)-OH).

1H NMR confirms,

1.56 δ (4H, triplet) - (-CH₂-CH₂-CH-OH) ; triplet as coupling with 2 H,

1.78 δ (4H, multiplet) - (-CH₂-CH₂-CH-OH); multiplet as coupling with 2H of CH₂, 1 H of CH

3.24 δ (1H, quintet); - (-CH₂-CH₂-CH(CH₂-)-OH), coupling with4 H of 2 group of CH₂

3.58 δ (1H, singlet); - (-CH₂-CH₂-CH(CH₂-)-OH), hydrogen of alcohol group, not tend to coupling with other hydrogen

4 0

3 years ago

For the following reaction, 22.6 grams of nitrogen monoxide are allowed to react with 4.64 grams of hydrogen gas . nitrogen mono

antiseptic1488 [7]

Answer:

- 10.5 g of N₂

- Limiting reagent: NO

- 3.13 g of H₂ remains

Explanation:

First of all we state the reaction: 2NO(g) + 2H₂(g) → 2H₂O(l) + N₂(g)

We need to find out the limiting reactant and the excess reagent

Ratio in the reactants is 2:2. Let's convert the mass to moles:

22.6 g / 30 g/mol = 0.753 moles of NO

4.64 g / 2 g/mol = 2.32 moles of H₂

Certainly the limiting reagent is the NO and the excess reactant is the hydrogen:

- For 0.753 moles of NO, we need 0.753 moles of H₂ (we have 2.32 moles)

- For 2.32 moles of H₂, we need 2.32 moles of NO (and we don't have enough NO, because we only have 0.753 moles)

As the H₂ is the excess reagent, some moles still remains after the reaction is complete → 2.32 mol - 0.753 mol = 1.567 moles

We convert the moles to mass: 1.567 mol . 2g /1mol = 3.13 g of H₂ remains

As the NO is the limiting reagent, we can work with the equation:

We propose this rule of three: 2 moles of NO can produce 1 mol of N₂

Then, 0.753 moles of NO must produce (0.753 . 1) /2 = 0.376 moles of N₂

We convert the moles to mass 0.376 mol . 28 g / 1 mol = 10.5 g

3 0

3 years ago

Describe where a hydrogen bond can form among water molecules.

stiv31 [10]

Answer:

In water hydrogen bonding formed between partially negative oxygen and partially positive hydrogen atoms.

Explanation:

Hydrogen bond is a partially electrostatic attraction between hydrogen (H), which is bonded to a more electronegative atom such as nitrogen (N), oxygen (O) or fluorine (F), and another adjacent atom bearing a lone pair of electrons.

In water molecule hydrogen and oxygen have difference in electronegativity, due to which dipoles are form. One is partial positive on hydrogen atom and other is partial negative on oxygen atom. The electrostatic attraction occur between two oppositely charged poles which is known as hydrogen bonding.

4 0

3 years ago