All categories

3 years ago

how many moles of water H2O contain 2.0 x 10^22 molecules of water? express the quantity in moles to two significant figures

1 answer:

7 0

1 mole ------------- 6.02x10²³ molecules
?? moles ---------- 2.0x10²² molecules

( 2.0 x 10²² ) x 1 / 6.02x10²³ => <span>0.0332 moles of water</span>

You might be interested in

How many atoms are in C₆H₁₂O₆

N76 [4]

Answer:

There are 24 atoms in one molecule of C6 H12 06. This chemical compound has 6 atoms of carbon, 12 atoms of hydrogen, and 6 atoms of oxygen.

3 0

2 years ago

Read 2 more answers

10 grams of sodium hydroxide, NaOH, is dissolved in 0.25 liters of solution. Determine the molarity (M).

lozanna [386]

Answer:

Explanation:

The molarity of a substance is defined as the number of moles of the substance divided by how many liters the solution is. NaOH has a molar mass of about 40 grams, meaning that 10 grams of it would be 0.25 moles. 0.25/0.25= a molarity of 1.

Hope this helps!

3 0

3 years ago

The __lithosphere__ combines the two crusts, oceanic and continental, with the coolest part of the __________________. The asthe

zmey [24]

Answer:

The lithosphere And the upper mantle combines the two crusts, oceanic and continental, with the coolest part of the Crust?. The asthenosphere allows the tectonic plates to slide on the putty substance of the mantle and the mesosphere is the Smallest? part of the mantle. The outer core is hot enough to turn the metal into a Liquid The inner core is the hottest but the extreme pressure makes it a Solid.

8 0

2 years ago

Read 2 more answers

Use the following equation to answer the questions below:

Gala2k [10]

Explanation:

The equation of the reaction is given as;

Be + 2HCl → BeCl2 + H2

What is the mass of beryllium required to produce 25.0g of beryllium chloride?

1 mol of Be produces 1 mol of BeCl2

Converting to mass;

Mass = Molar mass * Number of moles

9.01g of Be produces 79.92g of BeCl2

xg of Be produces 25g of BeCl2

Solving for x;

x = 25 * 9.01 / 79.92

x = 2.82 g

What is the mass of hydrochloric acid required to produce 25.0g of beryllium chloride? g

Converting 25.0g of beryllium chloride to moles;

Number of moles = Mass / Molar mass

Number of moles = 25 / 79.92 = 0.3128 mol

2 mol of HCl produces 1 mol of BeCl2

x mol of HCl would produce 0.3128 mol of BeCl2

solving for x;

x = 0.3128 * 2 = 0.6256 mol

Converting to mass;

Mass = 0.6256 * 36.5 = 22.83 g

What is the mass of hydrogen gas produced when 25.0g of beryllium chloride is also produced? g

25g of BeCl2 = 0.3128 mol of BeCl2

From the equation;

1 mol of H2 is produced alongside 1 mol of BeCl2

This means;

0.3128 mol of H2 would also be produced alongside 0.3128 mol of BeCl2

Mass = Number of moles * Molar mass

Mass = 0.3128mol * 2.0159 g/mol = 0.6306 g

3 0

3 years ago

The NaCl crystal structure consists of alternating Na⁺ and Cl⁻ ions lying next to each other in three dimensions. If the Na⁺ rad

Yuliya22 [10]

Answer : The radii of the two ions Cl⁻ ion and Na⁺ ion is, 181 and 102 pm respectively.

Explanation :

As we are given that the Na⁺ radius is 56.4% of the Cl⁻ radius.

Let us assume that the radius of Cl⁻ be, (x) pm

So, the radius of Na⁺ = $x\times \frac{56.4}{100}=(0.564x)pm$

In the crystal structure of NaCl, 2 Cl⁻ ions present at the corner and 1 Na⁺ ion present at the edge of lattice.

Thus, the edge length is equal to the sum of 2 radius of Cl⁻ ion and 2 radius of Na⁺ ion.

Given:

Distance between Na⁺ nuclei = 566 pm

Thus, the relation will be:

$2\times \text{Radius of }Cl^-+2\times \text{Radius of }Na^+=\text{Distance between }Na^+\text{ nuclei}$

$2\times x+2\times 0.564x=566$

$2x+1.128x=566$

$3.128x=566$

$x=180.9\approx 181pm$

The radius of Cl⁻ ion = (x) pm = 181 pm

The radius of Na⁺ ion = (0.564x) pm = (0.564 × 181) pm =102.084 pm ≈ 102 pm

Thus, the radii of the two ions Cl⁻ ion and Na⁺ ion is, 181 and 102 pm respectively.

4 0

3 years ago