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
Umnica [9.8K]
3 years ago
5

How many moles of Kr are contained in 398 mg of Kr?

Chemistry
1 answer:
bagirrra123 [75]3 years ago
8 0
The mass of 1 mole of an element is its atomic weight on the Periodic Table in grams.

1g = 1000mg

The mass of 1 mole of Kr = 83.80g Kr

Convert mg Kr to g Kr.

398mg Kr x (1g/1000mg) = 0.398g Kr

Convert g Kr to mol Kr.

0.398g Kr x (1mol Kr/83.80g Kr) = 4.75x10-3mol Kr
You might be interested in
What would be the composition and ph of an ideal buffer prepared from lactic acid (ch3chohco2h), where the hydrogen atom highlig
Mashutka [201]

Answer:

P_H =2.86

c=1.4\times 10^{-4}

Explanation:

first write the equilibrium equaion ,

C_3H_6O_3  ⇄ C_3H_5O_3^{-}  +H^{+}

assuming degree of dissociation \alpha =1/10;

and initial concentraion of C_3H_6O_3 =c;

At equlibrium ;

concentration of C_3H_6O_3 = c-c\alpha

[C_3H_5O_3^{-}  ]= c\alpha

[H^{+}] = c\alpha

K_a = \frac{c\alpha \times c\alpha}{c-c\alpha}

\alpha is very small so 1-\alpha can be neglected

and equation is;

K_a = {c\alpha \times \alpha}

[H^{+}] = c\alpha = \frac{K_a}{\alpha}

P_H =- log[H^{+} ]

P_H =-logK_a + log\alpha

K_a =1.38\times10^{-4}

\alpha = \frac{1}{10}

P_H= 3.86-1

P_H =2.86

composiion ;

c=\frac{1}{\alpha} \times [H^{+}]

[H^{+}] =antilog(-P_H)

[H^{+} ] =0.0014

c=0.0014\times \frac{1}{10}

c=1.4\times 10^{-4}

6 0
3 years ago
Given the following equation: Cu + 2 AgNO3 ---> Cu(NO3)2 + 2
Temka [501]

Given the following equation; Cu + 2AgNO3 = Cu(NO3)2 + 2Ag, 48.97 grams of Cu are needed to react with 262g of AgNO3.

<h3>How to calculate mass of substances?</h3>

The mass of a substance can be calculated using the following steps:

Cu + 2AgNO3 = Cu(NO3)2 + 2Ag

1 mole of Cu react with 2 moles of AgNO3

  • Molar mass of AgNO3 = 169.87 g/mol
  • Molar mass of Cu = 63.5g/mol

moles of AgNO3 = 262g/169.87g/mol = 1.54mol

1.54 moles of AgNO3 will react with 0.77 moles of Cu.

mass of Cu = 0.77 × 63.5 = 48.97g

Therefore, given the following equation; Cu + 2AgNO3 = Cu(NO3)2 + 2Ag, 48.97 grams of Cu are needed to react with 262g of AgNO3.

Learn more about mass at: brainly.com/question/6876669

8 0
2 years ago
Which statements are correct regarding the Law of Conservation of Matter and Energy?
Elden [556K]

Answer:

Matter or energy can change from one form to the other

Explanation:

The law of conservation of energy states that energy can neither be created nor destroyed but can only be transformed i.e. changed from one form to another. For example, mechanical energy can be changed to electrical energy.

Likewise, the law of conservation of mass/matter states that matter can not be destroyed or created but can change via physical or chemical means to conserve it. For example, matter can change from liquid state to gaseous state.

From the above two laws, it can be said that "matter or energy can change from one form to the other".

5 0
3 years ago
The solubility of alcohol decrease with increasing numbers of carbon atom explain​
Oxana [17]

The number of carbon atoms in an alcohol affects its solubility in water, as shown in Table 13.3. As the length of the carbon chain increases, the polar OH group becomes an ever smaller part of the molecule, and the molecule becomes more like a hydrocarbon. The solubility of the alcohol decreases correspondingly.

6 0
2 years ago
Someone please help me !!
Bezzdna [24]

Answer:

3

Explanation:

6 0
3 years ago
Other questions:
  • This formula equation is unbalanced.
    12·1 answer
  • What is the correct sequence of eras of the geologic time scale in order from oldest to youngest ?
    9·2 answers
  • A hydrocarbon is a compound that contains mostly carbon and hydrogen. Calculate the percent composition (by mass) of the followi
    9·1 answer
  • At 20 ∘C the vapor pressure of benzene C6H6 is 75 torr and that of toluene C7H8 is 22 torr. Assume that benzene and toluene fo
    11·1 answer
  • Which type of intermolecular attractive force operates between (part A) all molecules, (part B) polar molecules, (part C) the hy
    10·1 answer
  • Which state of matter will have a greater force of intermolecular attraction?
    15·1 answer
  • A chemist measures the amount of bromine liquid produced during an experiment. She finds that 14.4 g of bromine liquid is produc
    9·1 answer
  • What is the pH of a solution that contains 0.009 grams of oxalic acid in 100<br> mL of water?
    9·1 answer
  • SCIENCEEEE!!!!! HELPPPP!!!!
    13·2 answers
  • What does it mean that something is a conservative ion?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!