4. What do radio telescopes use to gather and focus radio waves?

A student working in the laboratory produces 6.81 grams of calcium oxide, CaO, from 20.7 grams of calcium

ozzi

Answer:

Percent yield = 57.8 %

Theoretical yield = 11.781 g

Explanation:

Given data:

Mass of CaO produced = 6.81 g

Mass of CaCO₃ react = 20.7 g

Theoretical yield = ?

Percent yield = ?

Solution:

Chemical equation:

CaCO₃ → CaO + CO₂

Number of moles of CaCO₃ :

Number of moles = mass/molar mass

Number of moles = 20.7 g/ 100.1 g/mol

Number of moles = 0.21 mol

Now we will compare the moles of CaCO₃ with CaO.

CaCO₃ : CaO

1 : 1

0.21 : 0.21

Theoretical yield of CaO:

Mass = number of moles × molar mass

Mass = 0.21 mol × 56.1 g/mol

Mass = 11.781 g

Percent yield:

Percent yield = ( actual yield / theoretical yield ) × 100

Percent yield = (6.81 g/ 11.781 g) × 100

Percent yield = 57.8 %

8 0

3 years ago

To power a flashlight for 1 second, we need ____________ of energy

Doss [256]

It is Kenetic energy

5 0

3 years ago

Read 2 more answers

Calculate the ratio of the mass ratio of SS to OO in SOSO to the mass ratio of SS to OO in SO2SO2. Consider a sample of SOSO in

Veronika [31]

Answer:

The ratio of the mass ratio of S to O; in SO, to the mass ratio of S to O; in SO₂, is 2:1

Explanation:

According to the consideration, let us first find the ratio of S and O in both the compounds

For SO:

$\frac{m_{S} }{m_{O} }= \frac{32}{16}\\\\ \frac{m_{S} }{m_{O} }= 2$

Let us express it as

$SO_{\frac{m_{S} }{m_{O} }} = 2$

For SO₂,

Due to two oxygen atoms in the molecule, the mass of oxygen will be taken two times

$\frac{m_{S} }{m_{O} }= \frac{32}{(2)(16)}\\\\ \frac{m_{S} }{m_{O} }= 1$

Let us express it as

$SO_2_{\frac{m_{S} }{m_{O} }}= 1$

Now, for the ratio of both the above-calculated ratios,

$\frac{SO_{\frac{m_{S} }{m_{O} }}}{SO_2_{\frac{m_{S} }{m_{O} }}}=\frac{2}{1}$

The required ratio is 2:1

3 0

3 years ago

How are magnetic objects able to be

Vadim26 [7]

Answer:

Explorations include static electricity, magnets, electromagnets and permanent magnets. Examples of cause and effect relationships could include how the distance between objects affects strength of the force and how the orientation of magnets affects the direction of the magnetic force.

Explanation:

4 0

3 years ago

How many moles of potassium are contained in 150 g of potassium

BaLLatris [955]

Answer:

150 g of potassium contained 3.8 moles of potassium.

Explanation:

Given data:

Mass of potassium = 150 g

Moles of potassium = ?

Solution:

Number of moles = mass/ molar mass

Molar mass of potassium = 39 g/mol

Now we will put the values in formula:

Number of moles = mass/ molar mass

Number of moles = 150 g/ 39 g/mol

Number of moles = 3.8 mol

150 g of potassium contained 3.8 moles of potassium.

3 0

4 years ago