1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Bezzdna [24]
3 years ago
13

Please help last assignment of the day

Chemistry
1 answer:
Andrej [43]3 years ago
3 0

In this qn, you use the mole formula,

amount (mol) = mass (g) ÷ molar mass

(molar mass is the mass number of an element, which u can find by referring to the periodic table)

so by subbing in the values given to you, you can find the answer

5. amount of Cu = 55.9 ÷ 63.5 = 0.880mol (3sf)

6. amount of N2 = 340 ÷ 2(14.0) = 12.1mol (3sf)

(note: you multiply the molar mass of N by 2 as there are 2 N atoms)

for qn 7 and 8, youre finding the mass and not the amount. By bringing the molar mass over to the other side of the formula, you get

mass = amount (mol) × molar mass

thus,

7. mass of Fe = 0.063 × 55.8 = 3.52g (3sf)

8. mass of H2 = 94.7 × 2(1.0) = 47.4g (3sf)

extra things to take note of:

- likewise, you can also find the molar mass of an element by using

molar mass = mass(g) ÷ amount(mol)

^^ this is commonly only needed when you need to find the molar mass of an isotope. the question will give you the amount and mass of the element, and you just need to factor them in to find your answer.

- typically, you use 3 sf in your final answer and 5sf in your working. remember to write (3sf) at the end of your number statement when necessary.

- when you get an answer of (eg.) 0.6mol, you still need to write it in 3sf, so your answer would be 0.600mol

You might be interested in
What compound are formed with lithium and selenium?
love history [14]

Answer:

Lithium selenide Lithium selenide (Li2Se) 12136-60-6 Dilithium selenide lithium selenidolithium

Molecular Weight 92.9 g/mol

Dates Modify 2020-11-15 Create 2005-08-08

5 0
3 years ago
Read 2 more answers
Explain whether areas B and D show the same season.
torisob [31]
They do not show the same season. one is faced a different part of the sun
4 0
2 years ago
se tienen 10 litros de nitrogeno gaseoso bajo una presion de 560 mm Hg. Determina el volumen del nitrogeno a una presion de 760
Dominik [7]

Answer:

working business city philadelphian

3 0
2 years ago
3. What mass of copper could be deposited from a copper(II) Sulphate solution using a current of 5.0 A over 100 seconds? ( F =96
arsen [322]

Mass of copper : 0.165 g

<h3>Further explanation</h3>

Given

5.0 A over 100 seconds

Required

Mass of copper

Solution

Faraday's law:

<em>The mass of the substance formed at each electrode is proportional to the electric current flowing in the electrolysis</em>

<em />\tt W=\dfrac{e.i.t}{96500}<em />

e = Ar / valence = eqivalent weight

i = current

t = time

W = weight

CuSO₄ ----> Cu²⁺ + SO₄²⁻

Cu ----> Cu²⁺ + 2e

e = Ar/2

= 63,5/2 = 31,75

\tt W=\dfrac{31.75\times 5\times 100}{96500}=0.165~g

8 0
2 years ago
A. amplitude<br> B. frequency<br> C. pitch<br> D. speed
Liono4ka [1.6K]
What is the question!
6 0
2 years ago
Read 2 more answers
Other questions:
  • A gas sample at stp contains 1.15 g oxygen gas and 1.55 g nitrogen gas.what is the volume of the gas sample?
    8·2 answers
  • Which element had the longest effect on human history?
    8·1 answer
  • How many moles of gas would occupy a 25.0 liter when the temp is 22.0 degrees celsius and the pressure is 646 torr
    10·1 answer
  • Calculate the number of molecules in a deep breath of air whose volume is 2.15 L at body temperature, 37 ∘C, and a pressure of 7
    14·2 answers
  • Two elements in the second transition series (Y through
    9·2 answers
  • What is the attraction between atoms when they react called?
    13·1 answer
  • The matter through which waves travel is called a/an​
    5·1 answer
  • Which of the following is true about extinction? A. Only one extinction has occurred during the Earth's history. B. Plant specie
    6·2 answers
  • Why does the mass of steel wool increase after getting burned? Help pls
    7·1 answer
  • How many significant figures are needed in the answer when 1.31m is multiplied by 6.5 m​
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!