All categories

2 years ago

What is the basic unit of chemistry?

Chemistry

2 answers:

Luba_88 [7]2 years ago

7 0

An atom hopefully this helps

ololo11 [35]2 years ago

7 0

An atom is the basic unit of chemistry

You might be interested in

Na is best known as a(n):

Lady bird [3.3K]

Answer:0

Explanation:

tfnjgjvtjgjvjv

8 0

2 years ago

Read 2 more answers

A solution of HNO3HNO3 is standardized by reaction with pure sodium carbonate. 2H++Na2CO3⟶2Na++H2O+CO2 2H++Na2CO3⟶2Na++H2O+CO2 A

Gemiola [76]

Answer:

(0,653±0,002) M of HNO₃

Explanation:

The reaction of standarization of HNO₃ with Na₂CO₃ is:

2 HNO₃ + Na₂CO₃ ⇒ 2 Na⁺ + H₂O + CO₂ + 2NO₃⁻

To obtain molarity of HNO₃ we need to know both moles and volume of this acid. The volume is (27,71±0,05) mL and to calculate the moles it is necessary to obtain the Na₂CO₃ moles and then convert these to HNO₃ moles, thus:

0,9585 g of Na₂CO₃ × ( 1 mole / 105,988 g) =

9,043×10⁻³ mol Na₂CO₃ × ( 2 moles of HNO₃ / 1 mole of Na₂CO₃) = 1,809×10⁻² moles of HNO₃

Molarity is moles divide liters, thus, molarity of HNO₃ is:

1,809×10⁻² moles / 0,02771 L = 0,6527 M of HNO₃

The absolute uncertainty of multiplication is the sum of relative uncertainty, thus:

ΔM = 0,6527M× (0,0007/0,9585 + 0,001/105,988 + 0,05/27,71) =

0,6527 M× 2,54×10⁻³ = 1,7×10⁻³ M

Thus, molarity of HNO₃ solution and its absolute uncertainty is:

(0,653±0,002) M of HNO₃

I hope it helps!

5 0

3 years ago

Write the balanced equation for the decomposition of hydrogen peroxide to form water and oxygen.

Lerok [7]

Hydrogen peroxide is H2O2, while water is H2O and oxygen (a diatomic gas) is O2. The (unbalanced) reaction is:
H2O2 --> H2O + O2
Notice that the H2O2 has 2 H atoms, and so does H2. This means that both must have the same coefficients, and we can adjust the coefficient of O2. Since H2O2 has 2 O atoms, and H2O has 1, we multiply O2 by 1/2:
H2O2 --> H2O + (1/2)O2
This has an equivalent number of H and O atoms on either side, but we want the coefficients to be whole numbers, so we multiply everything by 2:
2H2O2 --> 2H2O + O2

7 0

2 years ago

30g of naoh is dissolved in 1.5 liter solution the active mass of naoh is?

Pepsi [2]

Answer:

0.5mol/L

Explanation:

First, let us calculate the number of mole NaOH = 23 + 16 + 1 = 40g/mol

Mass of NaOH from the question = 30g

Number of mole = Mass /Molar Mass

Number of mole = 30/40 = 0.75mol

Volume = 1.5L

Active mass = mole/Volume

Active mass = 0.75mol/1.5L

Active mass = 0.5mol/L

7 0

3 years ago

If 0.089 grams of KI is dissolved in 500g of H2O, what is the concentration of the resulting solution in parts per million?

frez [133]

Answer:

The concentration of the resulting solution in parts per million is 177.97

Explanation:

Parts per million (ppm), is a unit of measure for concentration that refers to the number of units of the substance per million units of the set.

The concentration in parts per million expressed in mass / mass is calculated by dividing the mass of the solute (ms) by the mass of the solution (md, sum of the mass of the solute and the mass of the solvent), both expressed in the same unit and multiplied by 10⁶ (1 million).

$ppm=\frac{ms}{md} *10^{6}$

So, being:

ms: 0.089 grams of KI

md: 0.089 grams of KI + 500 grams of H₂O= 500.089 grams

Replacing:

$ppm=\frac{0.089 grams}{500.089 grams}*10^{6}$

ppm= 177.97

<u><em>The concentration of the resulting solution in parts per million is 177.97</em></u>

6 0

3 years ago