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
Otrada [13]
3 years ago
10

How many total atoms are in 0.240 g of P2O5?

Chemistry
1 answer:
RSB [31]3 years ago
3 0
The answer is 1.02 × 10²⁵ atoms.

1. Calculate molar mass (Mr) of P2O5 which is the sum of atomic masses (Ar) of its elements:
Ar(P) = 31 g/mol
Ar(O) = 16
Mr(P2O5) = 2 * Ar(P) + 5 * Ar(O) = 2 * 31 + 5 * 16 = 62 + 80 = 142 g/mol

2. Calculate number of moles (n) which is the quotient of a sample mass (m) and the molar mass (Mr): 
n = m/Mr
m = 0.240 g
Mr = 142 g/mol
n = 0.240 / 142 = 0.0017 mol


3. Avogadro's number is the number of units atoms in 1 mole of substance:
<span>6.023 × 10²³ atoms per 1 mol
x atoms are per 0.0017 mol

</span>6.023 × 10²³ atoms : 1 mol = x atoms : 0.0017 mol
x = 6.023 × 10²³ atoms * 0.0017 mol : 1 mol
x = 0.0102 × 10²³ = 1.02 × 10² × 10²³ = 1.02 × 10²⁵ atoms
You might be interested in
Which material is not a metamorphic rock
ASHA 777 [7]
Letter C would be the correct answer
3 0
3 years ago
PLS HELP ME I HAVE TILL 12
MariettaO [177]

Answer:

alright bud lets see hmm.... the answer is a. 90.5kpa

Explanation:

92.3 kPa - 1.82 kPa = 90.5 kPa

keep up your hope also corrected me if a am wrong in anyway! :)

3 0
3 years ago
Please help with 3! Please give only the correct answer...
cupoosta [38]
The answer is:  " 1.75 * 10 ^(-10)  m " .
_________________________________________________________
Explanation: 
_________________________________________________________
This very question asked for "Question Number 3 (THREE) ONLY, which is fine!
_________________________________________________________
Given: " 0.000000000175 m " ;  write this in "scientific notation.
_________________________________________________________
Note:   After the "first zero and the decimal point" {Note: that first zero that PRECEDES the decimal point in merely a "placeholder" and does not count as a "digit" — for our purposes} —
                     There are NINE (9) zeros, followed by "175"
_______________________________________________________
To write in "scientific notation", we find the integer that is written, as well, as any "trailing zeros" (if there are any—and by "trailing zeros", this means any number consecutive zeros/and starting with "the consecutive zeros" only —whether forward (i.e., "zeros following"; or backward (i.e. "zeros preceding").

In our case we have "zeros preceding";  that is a decimal point with zeros PRECEDING an "integer expression"<span>
</span><span> (the "integer" is "175").</span>
______________________________________________________
We then take the "integer expression" (whatever it may be:  12, 5, 30000001 ; or could be a negative value,  etc.) ;  

→  In our case, the "integer expression" is:  "175" ;

and take the first digit (if the expression is negative, we take the negative value of that digit;  if there is only ONE digit (positive or negative), then that is the digit we take ;

And write a decimal point after that first digit (unless in some cases, there is only one digit);  and follow with the rest of the consecutive digits of that 'integer expression' ;

→ In our case:  "175" ; becomes:  " 1.75" .
__________________________________________________
Then we write:  "  * 10^ "
__________________________________________________
   {that is "[times]"; or "multiplied by" :    [10 raised exponentially to the power of  <u>     </u> ]._____________________________________________________
 And to find that power, we take the "rewritten integer value (i.e. "whole number value that as been rewritten to a single digit with a decimal point"); and count the [number of "trailing zeros";  if there are any; PLUS the number of decimal places one goes] ; and that number is the value to which "10" is raised.
{If there are none, we write:  " * 10⁰ " ;    since "any value, raised to the "zero power", equals "1" ; so " * 10⁰ " ; is like writing:  " * 1 " .

If there are "trailing zeros" AND/OR or  any number of decimal places,  to the "right" of this expression; the combined number of spaces to the right is: 
  { the numeric value (i.e. positive number) of the power to which "10" is raised }.

Likewise, if there are "trailing zeros" AND/OR or any number of decimal places, to the "LEFT" of this expression; the combined number of spaces to the LEFT is the value of the power which "10" is raised to; is that number—which is a negative value.

In our case:  we have:  0.000000000175 * 10^(-10) .

Note:  The original notation was:

             →  " 0.000000000175 m "

{that is:  "175" [with 9 (nine) zeros to the left].}.

We rewrite the "175" ("integer expression") as:

"1.75" .
____________________________________________________
So we have:
         →   " 0.000000000175 m " ;

Think of this value as:

        " 0. 0000000001{pseudo-decimal point}75   m ".

And count the number of decimal spaces "backward" from the
      "pseudo-decimal point" to the actual decimal; and you will see that there are "10" spaces (to the left).   
______________________________________________________
Also note:  We started with "9 (nine)" preceding "zeros" before the "1" ;  now we are considering the "1" as an "additional digit" ;
             →  "9 + 1 = 10" .
______________________________________________________
Since the decimals (and zeros) come BEFORE (precede) the "175" ; that is, to the "left" of the "175" ; the exponent to which the "10" is raised is:
 "NEGATIVE TEN" { "-10" } .

So we write this value as:  " 1.75 * 10^(-10)  m " .  

{NOTE:  Do not forget the units of measurement; which are "meters" —which can be abbreviateds as:  "m" .} . 
______________________________________________________
The answer is:  " 1.75 * 10^(-10)   m " .
______________________________________________________
4 0
3 years ago
At which point on the roller coaster will the car have the greatest amount of Kinetic energy?
Elena-2011 [213]
I’m going to say the answer is most likely X because memetic energy is energy being used at that moment. Because the coaster is going fastest at X we can assume that the answer is X
4 0
3 years ago
The relatively high boiling point of water is due to water having
Verizon [17]
The answer should be hydrogen bonding. Water only has oxygen and hydrogen in it, which are both nonmetals, so you know the answer cannot be metallic or ionic. It also cannot be nonpolar because the electronegativity of the oxygens will make the molecule polar. You can also know it is hydrogen bonding because it can only take place when a hydrogen is attached to an oxygen, fluorine, or nitrogen. These bonds are very strong attractions, so the molecules are extremely hard to pull apart, creating a high boiling point. Hope that helps!
3 0
3 years ago
Other questions:
  • Electronegativity increases as the size of the atom increases.<br> a. True<br> b. False
    13·1 answer
  • Which scientist performed the cathode ray experiment leading to the discovery of electrons?
    9·1 answer
  • Percent composition?: 85.05 g of Mg combines completely with 112.21 g of S.
    11·1 answer
  • A compound consists of 40.00% C, 6.713% H and 53.28% O on a mass basis and has a molar mass of about 180 g/mole. Determine the m
    9·1 answer
  • If 2 or more elements are involved in a chemical reaction, they will most likely form a/an
    5·1 answer
  • In the Minnesota Department of Health set a health risk limit for acetone in groundwater of 60.0 μg/L . Suppose an analytical ch
    5·1 answer
  • How many chloride ions are in a 220 grams of calcium chloride?
    12·1 answer
  • 54:63 ratio simplest form?
    11·1 answer
  • Electron configuration worksheet
    13·1 answer
  • What must happen for an electron to return to its original energy level from a higher energy level?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!