All categories

3 years ago

Which sample contains a total of 3.0 x 10^23 molecules?

1 answer:

3 0

Given that 1 mole contains 6.02x10^23 molecules, 3.0x10^23 is just around half a mole. Then we check the number of moles for each choice:

A. This is approximately half a mole, since the molar mass of Br2 is 159.8 g/mol.
B. He has a molar mass around 4 g/mol, so this is 1 mole.
C. H2 has a molar mass of 2.02 g/mol, so this is 2 moles.
D. Li has a molar mass of around 6.97 g/mol, so this is around 2 moles.

Therefore the only choice that fits is A. 80 g of Br2.

You might be interested in

Hi, how are you today i want you to answer this question please because it’s homework for my sister and she have to show the tea

vfiekz [6]

Answer:

The Earth's surface is constantly changing through forces in nature. The daily processes of precipitation, wind and land movement result in changes to landforms over a long period of time. Driving forces include erosion, volcanoes and earthquakes. People also contribute to changes in the appearance of land.

3 0

3 years ago

Read 2 more answers

What element should I do a project on?

yarga [219]

Answer:

Project scope statement?

Explanation:

it's good one just do research on it

3 0

3 years ago

After creating a prototype, which of the following would not be an appropriate next step in the design process of a new technolo

Ivanshal [37]

I would say D but i am not entirely sure

4 0

3 years ago

Which of the following molecules experience dipole-dipole forces as its strongest IMF? A) H2 B) SO2 C) NH3 D) CF4 E) BCl3

Xelga [282]

Answer: $NH_3$

Explanation:

a) $H_2$ : This is a non polar covalent compound which are held by weak vanderwaal forces of attraction.

b) $SO_2$ : This is a covalent compound which is polar due to the presence of lone pair of electrons and are held by dipole-dipole forces of attraction.

c) $NH_3$ : These are joined by a special type of dipole dipole attraction called as hydrogen bond. It forms between electronegative nitrogen atom and hydrogen atom and is the strongest interaction.

d) $CF_4$ : This is a covalent compound and is non polar which are held by weak vanderwaal forces of attraction.

e) $BCl_3$ : This is a covalent compound and is non polar which are held by weak vander waal forces of attraction.

5 0

3 years ago

A sample of g of pure aluminum metal is added to mL of M hydrochloric acid. The volume of hydrogen gas produced at standard temp

MArishka [77]

Answer:

V = 11.2L are produced

Explanation:

... Sample of 27g of pure aluminium, 3added to 333 mL of 3.0 M HCl..

Based on the chemical reaction:

2Al(s) + 6HCl(aq) → 2AlC₃(aq) + 3H₂(g)

Where 3 moles of hydrogen are produced when 6 moles of hydrochloric acid reacts with 2 moles of Al.

To solve this question, we need to determine limiting reactant converting each reactant to moles. With limiting reactant and the chemical reaction we can find moles of hydrogen and its volume at STP (T=273.15K; P=1atm), thus:

Moles Al-Molar mass: 26.98g/mol-:

27g * (1mol / 26.98g) = 1mol of Al

Moles HCl:

333mL = 0.333L * (3mol/L) = 1mol HCl

For a complete reaction of 1 mole of HCl are required:

1mol HCl * (2mol Al / 6mol HCl) = 0.333 moles of Al. As there is 1 mole of Al, Al is in excess and HCl is limiting reactant.

Moles of Hydrogen produced are:

1mol HCl * (3 moles H₂ / 6 mol HCl) = 0.5moles H₂ are produced.

Using ideal gas law:

PV = nRT

V = nRT/P

Where V is volume

n are moles: 0.5mol

R is gas constant: 0.082atmL/molK

T is absolute temperature: 273.15K

P is pressure: 1atm.

Solving for V:

V = 0.5mol*0.082atmL/molK*273.15K / 1atm

<h3>V = 11.2L are produced</h3>

3 0

3 years ago