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3 years ago

2. Give a "water-wise" alternative to each

Chemistry

1 answer:

Kitty [74]3 years ago

4 0

Answer:

1. sweep it instead

2.use a wateringcan with a percise nossole to water your plants efectivly 3.keep a jug of water in your frisge

Explanation:

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Alveoli are tiny sacs of air in the lungs. Their average diameter is 4.50 × 10−5 m. Calculate the uncertainty in the velocity of

Arisa [49]

<u>Answer:</u> The uncertainty in the velocity of oxygen molecule is $4.424\times 10^{-5}m/s$

<u>Explanation:</u>

The diameter of the molecule will be equal to the uncertainty in position.

The equation representing Heisenberg's uncertainty principle follows:

$\Delta x.\Delta p=\frac{h}{2\pi}$

where,

$\Delta x$ = uncertainty in position = d = $4.50\times 10^{-5}m$

$\Delta p$ = uncertainty in momentum = $m\Delta v$

m = mass of oxygen molecule = $5.30\times 10^{-26}kg$

h = Planck's constant = $6.627\times 10^{-34}kgm^2/s^2$

Putting values in above equation, we get:

$4.50\times 10^{-5}m\times 5.30\times 10^{-26}kg\times \Delta v=\frac{6.627\times 10^{-34}kgm^2/s}{2\times 3.14}\\\\\Delta v=\frac{6.627\times 10^{-34}kgm^2/s^2}{2\times 3.14\times 4.50\times 10^{-5}m\times 5.30\times 10^{-26}kg}=4.424\times 10^{-5}m/s$

Hence, the uncertainty in the velocity of oxygen molecule is $4.424\times 10^{-5}m/s$

8 0

3 years ago

Unit: Stoichiometry

Reika [66]

Answer:

1. 2.41 × 1023 formula units

2. 122 L

3. 7.81 L

Explanation:

1. Equation of the reaction: 2 Na(NO3) + Ca(CO3) ---> Na2(CO3) + Ca(NO3)2

Mole ratio of NaNO3 to CaCO3 = 2 : 1

Moles of CaCO3 = mass/molar mass

Mass of CaCO3 = 20 g; molar mass of CaCO3 = 100 g

Moles of CaCO3 = 20 g/100 g/mol = 0.2 moles

Moles of NaNO3 = 2 × 0.2 moles = 0.4 moles

1 Mole of NaNO3 = 6.02 × 10²³ formula units

0.4 moles of NaNO3 = 0.4 × 6.02 × 10²³ = 2.41 × 1023 formula units

2. Equation of reaction : 2 H2O ----> 2 H2 + O2

Mole ratio of oxygen to water = 1 : 2

At STP contains 6.02 × 10²³ molecules = 1 mole of water

6.58 × 10²⁴ molecules = 6.58 × 10²⁴ molecules × 1 mole of water/ 6.02 × 10²³ molecules = 10.93 moles of water

Moles of oxygen gas produced = 10.93÷2 = 5.465 moles of oxygen gas

At STP, 1 mole of oxygen gas = 22.4 L

5.465 moles of oxygen gas = 5.465 moles × 22.4 L/1 mole = 122 L

3.Equation of reaction: 6 K + N2 ----> 2 K3N

Mole ratio of Nitrogen gas and potassium = 6 : 1

Moles potassium = mass/ molar mass

Mass of potassium = 90.0 g, molar mass of potassium = 39.0 g/mol

Moles of potassium = 90.0 g / 39.0 g/mol = 2.3077moles

Moles of Nitrogen gas = 2.3077 moles / 6 = 0.3846 moles

At STP, 1 mole of nitrogen gas = 22.4 L

0.3486 moles of oxygen gas = 0.3486 moles × 22.4 L/1 mole = 7.81 L

7 0

3 years ago

Why is there a vast amount of salt water on earth

kogti [31]

Its probably becuase of the amount of minerals found in the ocean floor.Salt just so happens to be a major one.not only that,but the amount of salt that the human body emits while while outside,normally by bodies of water,it could also be that.

6 0

3 years ago

Read 2 more answers

Does a physical change make a new substance

sasho [114]

Answer:

no it does not fftyhhhhhhvvvv

6 0

3 years ago

Consider the following solutions: 0.010 m Na3PO4 in water 0.020 m CaBr2 in water 0.020 m KCl in water

Helen [10]

Answer:

a) KI and Na₃PO₄

b) HF

c) CaBr₂

Explanation:

The depression in freezing point, relative lowering of vapor pressure and elevation in boiling point are colligative properties.

The collegative properties depend upon the number of solute particles.

Let us see the concentration of particles in each of the given solutions:

a) 0.010 m Na₃PO₄ in water : each molecule will give three sodium ions and one phosphate ion.

So the concentration of particles in the solution = 4 X 0.01 = 0.04 m

b) 0.020 m CaBr₂ in water : each molecule will give one calcium ion and two bromide ion thus the concentration of particles in the solution

= 3 X 0.02 = 0.06 m

c) 0.020 m KCl in water: each molecule gives two ions thus the concentration of solution = 2 X 0.02 = 0.04 m

d) 0.020 m HF (weak acid) in water: the acid is weak, so each molecule will not give two ions completely (complete dissociation will not be observed). concentration of solution will be more than 0.02 but less than 0.04.

a) Both KCl and Na₃PO₄ will have same boiling point as 0.04 C₆H₁₂O₆.

b) the solution with least concentration of solute will have highest pressure. Thus HF is the answer,

c) the largest depression will be in the solution with highest solute concentration: Answer: CaBr₂.

8 0

3 years ago