2. Give an example of a "system". (2

What’s the ionic equation for lithium + water

disa [49]

Answer:

2Li(s) + 2H₂O(ℓ) ⟶ 2Li⁺(aq) + 2OH⁻(aq) + H₂(g)

Explanation:

An ionic equation uses the symbols (aq) [aqueous] to indicate molecules and ions that are soluble in water, (s) [solid] to indicate insoluble solids, and (ℓ) to indicate substances (usually water) in the liquid state.

In this reaction, solid lithium reacts with liquid water to form soluble lithium hydroxide and gaseous hydrogen .

1. Molecular equation

2Li(s) + 2H₂O(ℓ) ⟶ 2LiOH(aq) + H₂(g)

2. Ionic equation

Lithium hydroxide is a soluble ionic compound, so we write it as hydrated ions.

2Li(s) + 2H₂O(ℓ) ⟶ 2Li⁺(aq) + 2OH⁻(aq) + H₂(g)

7 0

3 years ago

Which elements make up 95 percent (by weight) of the human body?

Alex17521 [72]

Oxygen,carbon,hydrogen,and nitrogen- together make up 95 percent of the mass of the human body.
Hope this helps.

3 0

3 years ago

A 25.0 mL sample of an acetic acid solution is titrated with a 0.175 M NaOH solution. The equivalence point is reached when 26.6

joja [24]

Answer: The concentration of $CH_3COOH$ comes out to be 0.16 M.

Explanation:

To calculate the concentration of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $CH_3COOH$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is NaOH.

We are given:

$n_1=1\\M_1=?M\\V_1=25mL\\n_2=1\\M_2=0.175M\\V_2=26.6mL$

Putting values in above equation, we get:

$1\times M_1\times 25=1\times 0.175\times 26.6\\\\M_1=0.1862M$

Hence, the concentration of $CH_3COOH$ comes out to be 0.1862 M.

4 0

3 years ago

In which level of organization would the roots of a plant most likely be classified make sure to explain too

o-na [289]

Answer:

the biological levels of organization of living things arranged from the simplest to most complex are organelle , cells , tissues , organs , organ system , organism , population , communities , ecosystem , and biosphere....

Explanation:

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4 0

3 years ago

Nitric acid and nitrogen monoxide react to form nitrogen dioxide and water, like this: At a certain temperature, a chemist finds

poizon [28]

Answer:

K = 3.3

Explanation:

Nitric acid, HNO3, reacts with nitrogen monoxide, NO, to produce nitrogen dioxide, NO2 and water H2O as follows:

2HNO3(g) + NO(g) → 3NO2(g) + H2O(g)

Where equilibrium constant, K, is:

K = [NO2]³[H2O] / [HNO3]²[NO]

[] is the molar concentration of each species at equilibrium.

To solve this question we need to find molarity of each gas and replace these in the equation as follows:

[NO2] -Molar mass NO2-46.0g/mol-

18.6g * (1mol/46.0g) = 0.404mol / 7.7L = 0.0525M

[H2O] -Molar mass:18.01g/mol-

236.7g * (1mol/18.01g) = 13.14 moles / 7.7L = 1.707M

[HNO3] -Molar mass:53.01g/mol-

16.2g * (1mol/53.01g) = 0.3056 moles / 7.7L = 0.0397M

[NO] -Molar mass: 30.0g/mol-

11.0g * (1mol/30.0g) = 0.367 moles / 7.7L = 0.0476M

Replacing:

K = [NO2]³[H2O] / [HNO3]²[NO]

K = [0.0525M]³[1.707M] / [0.0397M]²[0.0476M]

4 0

3 years ago