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3 years ago

I need help with that box

Chemistry

1 answer:

valkas [14]3 years ago

6 0

I hope this helps.

the first line would be SN, 50, 50, 69

second line would be PT, 78, 78, 117

third line would be MO, 42, 42, 54

fourth line would be NI, 28, 28, 31

fifth line would be U, 92, 92, 146

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The graph below shows the volume and the mass of four different substances at STP.

sladkih [1.3K]

The formula of density is mass / volume

This means that
- high mass, low volume = high density
- high mass, high volume = so-so
- low mass, high volume = low density

From the graph shown,
D has the lowest density because it has low mass yet high volume.

6 0

3 years ago

Marcus measured the masses and volumes of samples of four different substances, and he calculated their densities. The table sho

Zina [86]

Given:

Calculated density values-

Aluminum = 2.7 g/cm3

Copper = 9.0 g/cm3

Iron = 7.9 g/cm3

Titanium = 4.8 g/cm3

Unknown sample mass = 9.5 g

Sample volume = 2.1 cm3

To determine:

The identity of the unknown sample

Explanation:

'Density' is a physical parameter which can be used to identify the nature of the unknown substance.

Density = Mass/Volume

For the unknown sample

Density = 9.5 g/2.1 cm3 = 4.52 g/cm3

This matches closely with the calculated density of titanium

Ans: The unknown substance is made of titanium

4 0

3 years ago

If you combine 27.1 g of a solute that has a molar mass of 27.1 g/mol with 100.0 g of a solvent, what is the molality of the res

baherus [9]

Answer: The molality of the solution is 0.1 m.

Explanation:

To calculate the molality of solution, we use the equation:

$Molality=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ in grams}}$

Where,

$m_{solute}$ = Given mass of solute = 27.1 g

$M_{solute}$ = Molar mass of solute = 27.1 g/mol

$W_{solvent}$ = Mass of solvent = 100 g

Putting values in above equation, we get:

$\text{Molality of solution}=\frac{27.1\times 1000}{27.1\times 100}\\\\\text{Molality of solution}=0.1m$

Hence, the molality of the solution is 0.1 m.

8 0

3 years ago

Read 2 more answers

Manganese(iv) oxide reacts with aluminum to form elemental manganese and aluminum oxide: 3mno2+4al→3mn+2al2o3part awhat mass of

Oxana [17]

12.4 g First, calculate the molar masses by looking up the atomic weights of all involved elements. Atomic weight manganese = 54.938044 Atomic weight oxygen = 15.999 Atomic weight aluminium = 26.981539 Molar mass MnO2 = 54.938044 + 2 * 15.999 = 86.936044 g/mol Now determine the number of moles of MnO2 we have 30.0 g / 86.936044 g/mol = 0.345081265 mol Looking at the balanced equation 3MnO2+4Alâ†’3Mn+2Al2O3 it's obvious that for every 3 moles of MnO2, it takes 4 moles of Al. So 0.345081265 mol / 3 * 4 = 0.460108353 mol So we need 0.460108353 moles of Al to perform the reaction. Now multiply by the atomic weight of aluminum. 0.460108353 mol * 26.981539 g/mol = 12.41443146 g Finally, round to 3 significant figures, giving 12.4 g

7 0

3 years ago

What are the major sources of crude oil

timurjin [86]

Explanation:

Crude oil is a naturally occurring fossil fuel - meaning it comes from the remains of dead organisms.

Crude oil is made up of a mixture of hydrocarbons - hydrogen and carbon atoms.

It exists in liquid form in underground reservoirs in the tiny spaces within sedimentary rocks. Or it can be found near the surface in oil sands.

It is often found alongside natural gas and saline water.

Crude oil is often interchangeably referred to as petroleum. This is because petroleum includes both the unrefined crude oil as well as refined petroleum products.

It is non-renewable - once it’s gone it’s gone and cannot be easily replaced.

5 0

3 years ago