Answer:7283
Explanation:
$34748
22.4 liters of CO2 at STP, 0◦C and 1 atm,
contains how many molecules? (Assume CO2
is an ideal gas.)
Answer:
There are [tex]6.01\times 10^{23}[/tex] number of molecules.
Explanation:
Given that,
Volume, V = 22.4 L
Temperature, T = 0°C = 273.15 K
Pressure, P = 1 atm = 1.013 bar
We need to find the number of molecules. Let there are n number of molecules. We know that, ideal gas law is as follows :
[tex]PV=nRT\\\\n=\dfrac{PV}{RT}\\\\n=\dfrac{1.013\times 22.4}{0.08 314\times 273.15}[/tex]
n = 0.999 moles
No. of molecules,
[tex]N=n\times N_A\\\\=0.999\times 6.023\times 10^{23}\\\\N=6.01\times 10^{23}[/tex]
So, there are [tex]6.01\times 10^{23}[/tex] number of molecules.
The carbon dioxide is released when limestone is heated during the
production of _____?
Carbon dioxide is released when limestone is heated during the production of [tex]\sf\purple{cement}[/tex]. ✔
[tex]\circ \: \: { \underline{ \boxed{ \sf{ \color{green}{Happy\:learning.}}}}}∘[/tex]
A chemist mixes 50.0mL of a 1.0M NaOH solution with 50.0mL of a 1.0M Ba(OH)2 solution. Assuming the two solutions are additive, what is the pH of the resulting solution
Answer:
[tex]pH=14.2[/tex]
Explanation:
Hello there!
In this case, according to the information in this problem, and considering these two bases are strong, it is necessary for us to calculate the total moles of OH ions as shown below:
[tex]n_{OH^-}^{from\ NaOH}=0.050L*1.0mol/L=0.050mol\\\\n_{OH^-}^{from\ Ba(OH)_2}=0.050L*1.0mol/L*2=0.10mol\\\\n_{OH^-}^{tot}=0.15mol[/tex]
Now, the as the solutions are additive, the total volume is then 0.100 L and the concentration:
[tex][OH^-]=\frac{0.15mol}{0.100L}=1.5[/tex]
And therefore, the pH is:
[tex]pH=14+log(1.5)\\\\pH=14.2[/tex]
Regards!
Science
How is the total magnification of a
cell calculated?
True or False all non - metal elements are gassed at room temperature.
Answer:
false
Explanation:
you have bromine , its a non metal and liquid in room temperature
The ionization energies required to remove successive electrons from one mole of calcium atoms are 590 kJ/mol, 1145 kJ/mol, 4912 kJ/mol, and 6474 kJ/mol. The most common ion of calcium is probably
Answer:
Ca^2+
Explanation:
As we know, more energy is required to remove an electron from a positively charged ion than is required to remove an electron from a neutral atom. Hence, the second ionization energy of calcium is greater than its first ionization energy.
However, the third and fourth ionization energies of calcium are much higher than the second ionization energy because they involve removal of electrons from an inner filed shell. This process requires a lot of energy and is often not feasible.
Hence, the most common ion of calcium must be Ca^2+ where only two electrons are removed from calcium.
6. The fusion of 4 H-1 nuclei to produce two positrons and one other nuclei.
Explanation:
Normally, fusion involves two heavy hydrogen nuclides but since we have 4 light hydrogen nuclides, two of which underwent positron emission, thus changing two protons into neutrons plus 2 positrons and 2 neutrinos. The resulting nucleus from this fusion reaction is an He-4 nucleus.
Can someone help me pleaseee
Answer:
D.
Explanation:
Answer
0°C
Explanation:
substance be formed in it's solid state
Select the mixture which is capable of tolerating addition of a strong acid without altering the pH? a.) 1.0 M HCl, 1.0 M NaCl b.) 1.0 M NH3,1.0 M NaCl c.) 1.0 M HF, 1.0 M NaCl d.) 1.0 M HNO2, 1.0 M NaNO2 e.) none
Answer:
d.) 1.0 M HNO2, 1.0 M NaNO2
Explanation:
A buffer is a mixture that is capable of tolerating addition of a strong acid or base without altering the pH substantially.
A buffer is the mixture of a WEAK ACID AND ITS CONJUGATE BASE or a WEAK BASE AND ITS CONJUGATE ACID
In the problems:
a) HCl is a strong acid and NaCl a salt. NO buffer
b) NH3 is a weak base and NaCL a salt. NO buffer
c) HF is a weak acid and NaCl a salt. NO buffer.
d) HNO2 is a weak acid and NaNO2 its conjugate base. A BUFFERPlease hurry Which of the following statements is true?
• A positively charged atom has more electrons than protons.
• A positively charged atom has more protons than neutrons.
• A positively charged atom has more neutrons than protons.
• A positively charged atom has no electrons.
• A positively charged atom has more protons than electrons.
Answer:
E, answer 5, A positively charged atom has more protons than electrons.
Explanation:
A 2.0 L flask contains nitrogen and oxygen gases at 25°C. The total pressure is 0.91 atm and contains 0.050 mol of nitrogen. Calculate the partial pressure of oxygen and moles of oxygen present
Answer:
.025 ml 02
Explanation:
I made a pdf and pasted it in and etc
When we send electricity to pass through electrolysis jar we see gas bubble around both electrodes. Water electrolysis produces 30cm3 at cathode. a. What gas does it appear at each electrode? b. What would you do to identify the gas in the test tubes at each electrode? c. Calculate the volume of gas which appears at anode.
Answer:
a) anode - hydrogen gas
cathode - oxygen gas
b) hydrogen gas - The gas burns with a pop sound
Oxygen gas - The gas rekindles a glowing splint
c) The volume of gas produced at the anode is 60cm3
Explanation:
The electrolysis of water produces two volumes of hydrogen at the anode and one volume of oxygen at the cathode.
The hydrogen gas burns with a pop sound. It is easily identified by this test. Also, oxygen is known to rekindle a glowing splint and this is a commonly used test for oxygen gas.
Since the ratio of hydrogen produced at the anode to oxygen produced at the cathode is 2:1 by volume; then when 30cm3 of oxygen is produced at the cathode, 60cm3 of hydrogen is produced at the anode.
5.) If 6 moles of Oxygen Gas (O2) are produced in the reaction below, how
many grams of Potassium Chloride (KCI) are also produced? *
2 KCIO3 → 2 KCI + 3 O2
Answer:
im really sorry but i dont no☹
When H forms a bond with H2O to form the hydronium ion H3O , this bond is called a coordinate covalent bond because
Answer:
both bonding electrons come from the oxygen atom
Explanation:
A coordinate covalent bond is said to be formed when an electron pair is donated into a empty orbital of an atom from a filled orbital of another atom.
In this type of covalent bond, the shared electron pair is furnished by only one of the bonding species.
The bonding between H^+ and H2O to form H3O^+ involves donation of a lone pair of electrons on oxygen into the empty 1s orbital of H^+ hence the two bonding electrons come from oxygen. This is why the bond is called a coordinate covalent bond.
Calculate the mass of an object that has a density of 3.52g/cm^3 and
a volume of 5000 cm^3. Note that Mass = Volume X Density
Answer:
17.6kg
Explanation:
mass = Volume × Density
mass = 5000cm^3 × 3.52g/cm^3
mass = 17600g = 17.6kg
define restivity and conductivity?
Answer:
Electrical resistivity is a property of a material that tells you how much it resists the flow of electric current, while conductivity quantifies how easily current flows.
Imagine you had HCl with a concentration of exactly 0.10 mol/dm3. If 0.023 dm3 of a sodium hydroxide solution, NaOH (aq), could exactly neutralize 0.040 dm3 of the HCl solution, what is the concentration of the NaOH (aq)
Answer:
Explanation:
Step 1: Calculate the amount of sodium hydroxide in moles
Volume of sodium hydroxide solution = 25.0 ÷ 1,000 = 0.0250 dm3
Rearrange:
Concentration in mol/dm3 =
Amount of solutein mol = concentration in mol/dm3 × volume in dm3
Amount of sodium hydroxide = 0.100 × 0.0250
= 0.00250 mol
Step 2: Find the amount of hydrochloric acid in moles
The balanced equation is: NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
So the mole ratio NaOH:HCl is 1:1
Therefore 0.00250 mol of NaOH reacts with 0.00250 mol of HCl
Step 3: Calculate the concentration of hydrochloric acid in mol/dm3
Volume of hydrochloric acid = 20.00 ÷ 1000 = 0.0200 dm3
Concentration in mol/dm3 =
Concentration in mol/dm3 =
= 0.125 mol/dm3
Step 4: Calculate the concentration of hydrochloric acid in g/dm3
Relative formula mass of HCl = 1 + 35.5 = 36.5
Mass = relative formula mass × amount
Mass of HCl = 36.5 × 0.125
= 4.56 g
So concentration = 4.56 g/dm3
The boat shown in the photo below is moving along at a constant 20 miles per hour. Is the boat accelerating? Question 3 options: A. No because it is not speeding up B. Yes because it is changing direction C. No because it is not slowing down D. Yes because the velocity is staying constant
Answer:
A
Explanation:
If its going at a constant speed it will not accelarate wich means to speed up.
50 POINTS PLEASE HELP!
A gas diffuses 1/7 times faster than hydrogen gas (H2).
What is the molar mass of the gas?
100.10 g/mol
98.78 g/mol
86.68 g/mol
79.98 g/mol
Answer: The molar mass of the gas is 9.878 g/mol.
Explanation:
According to Graham's law, the rate of diffusion is inversely proportional to square root of molar mass of gas.
[tex]Rate = \frac{1}{\sqrt{M}}[/tex]
where,
M = molar mass of gas
As given gas diffuses 1/7 times faster than hydrogen gas. So, its molar mass is calculated as follows.
[tex]\frac{R_{1}}{R_{2}} = \sqrt{\frac{M_{2}}{M_{1}}}\\[/tex]
where,
[tex]M_{1}[/tex] = molar mass of hydrogen gas
[tex]M_{2}[/tex] = molar mass of another given gas
[tex]R_{1}[/tex] = rate of diffusion of hydrogen
[tex]R_{2}[/tex] = rate of diffusion of another given gas = [tex]\frac{1}{7}R_{1}[/tex]
Substitute the values into above formula as follows.
[tex]\frac{R_{1}}{R_{2}} = \sqrt{\frac{M_{2}}{M_{1}}}\\\frac{R_{1}}{\frac{1}{7}R_{1}} = \sqrt{\frac{M_{2}}{2}}\\7 \times 1.414 = M_{2}\\M_{2} = 9.878 g/mol[/tex]
Thus, we can conclude that the molar mass of the gas is 9.878 g/mol.
Answer:
98.78 g/mol
Explanation:
Just took the test
A student performed the following reaction in his Chemistry class: Zn + 2HCl ---> ZnCl2+H2. He started with 32.70 g of Zn metal and 18.23 g HCl and got 60.1 g of of ZnCl2.
(I) How much ZnC12 should he have produced?
(II) What was his percentage yield?
(III) If the 32.70 g of Zinc that he started with contained impurities (materials other than Zinc), will this support the student's percentage yield?
Explain briefly.
Answer:
(I) [tex] m_{ZnCl_{2}} = 34.07 g [/tex]
(II) [tex] \% y = 176.4 \% [/tex]
(III) The presence of impurities in the 32.70 g of zinc will support the student's percentage yield.
Explanation:
The reaction is:
Zn + 2HCl → ZnCl₂ + H₂
(I) To find the number of moles of ZnCl₂ we need to calculate the number of moles of the reactants.
[tex] n_{Zn} = \frac{m}{A} [/tex]
Where:
m: is the mass
A: is the standard atomic weight
[tex] n_{Zn} = \frac{32.70 g}{65.38 g/mol} = 0.50 moles [/tex]
[tex] n_{HCl} = \frac{18.23 g}{36.458 g/mol} = 0.50 moles [/tex]
If 1 mol of Zn reacts with 2 moles of HCl, the number of moles of Zn needed to react with 0.50 moles of HCl is:
[tex] n_{Zn} = \frac{1 mol Zn}{2 moles HCl}*0.50 moles HCl = 0.25 moles [/tex]
Then, the limiting reactant is HCl. Now, we can find the number of moles of ZnCl₂ by knowing that 2 moles of HCl produce 1 mol of ZnCl₂.
[tex] n_{ZnCl_{2}} = \frac{1 mol ZnCl_{2}}{2 moles HCl}*0.50 moles = 0.25 moles [/tex]
Finally, the mass of ZnCl₂ that he has produced is:
[tex] m_{ZnCl_{2}} = n_{ZnCl_{2}}*M = 0.25 moles*136.286 g/mol = 34.07 g [/tex]
(II) The percentage yield can be found with the following equation:
[tex] \% y = \frac{m_{e}}{m_{t}} \times 100 [/tex]
Where:
[tex] m_{e}[/tex]: is the experimental mass = 60.1 g
[tex] m_{t}[/tex]: is the theoretical mass = 34.07 g
Hence, the percentage yield is:
[tex] \% y = \frac{60.1 g}{34.07 g} \times 100 = 176.4 \% [/tex]
(III) The presence of impurities in zinc will explain why the percentage yield is greater than 100% because the mass of the impurities will make the mass of zinc bigger than its mass without impurities. If there were no impurities in the zinc, its mass would be smaller and thus the percent yield.
I hope it helps you!
2CO +0, 200, what is the mole ratio of carbon monoxide to carbon
dioxide
A 1.2
B 2.2
C 2:1
D 3:1
Answer:
B. 2.2
Explanation:
A student was asked to determine the activity of four unknown metals W,X,Y and, Z.
Answer:
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
The activity of four unknown metals based on their chemical changes is option B.
What is a chemical change?Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.
There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.
There are three types of chemical changes:
1) inorganic changes
2)organic changes
3) biochemical changes
During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.
Learn more about chemical change,here:
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How many joules of heat is needed when 5 g of water is heated from 25°C to 75°C?
Answer:
1045 J
Explanation:
By using the formula Eh= mass×specific heat capacity × change in tempreture
With it being a known fact that the specific heat capacity of water is 4.16g/j/°c
The primary function of a chloroplast is to -
F . Convert food into energy a cell can use
G . Control the function of a cell and control genetic traits
H . Convert radiant energy into chemical energy through photosynthesis
J . Store water and nutrients
Please help!!!
what are the best topics to write a project work on EVS and Chemistry
Answer:
It is better to do chemistry
Explanation:
So that you will learn more of chemicals
Suggest whether potassium metal can be used to react with an acid to prepare a soluble salt. Explain your answer.
Yes, potassium metal can be used to react with an acid to prepare a soluble salt.
Acids react with metals to yield the corresponding metal salt and hydrogen gas.
One of the properties of metals is their ability to react with dilute acids to yield a soluble salt and hydrogen gas. This is a common reaction for all metals that are above hydrogen in the activity series.
Potassium can react with a hypothetical acid HB as follows;
2K(s) + 2HB(aq) ------> 2KB(aq) + H2(g)
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Can someone please help with these questions!! I would really appreciate it
Answer: water
Explanation: those elements all react to water , so the answer would be water . :)
1.How many moles of each element are in 0.0250 mol of K 2 Cr O 4? 2. How many moles of ammonium ions are in 4.50 mol of (N H 4 ) 2 CO 3 ? With all the process to see where you get the answers please
Answer:
1. 0.0500 moles K, 0.0250 moles Cr and 0.1000 moles O.
2. 9.00 moles ammonium ions are present.
Explanation:
1. In 1mol of K2CrO4 there are 2 moles of K, 1 mole of Cr and 4 moles of O.
The moles in 0.0250 moles K2CrO4 are:
0.0250mol * 2 = 0.0500 moles K
0.0250mol * 1 = 0.0250 moles Cr
0.0250mol * 4 = 0.1000 moles O
2. In 1 mole of (NH4)2CO3 there are 2 moles of ammonium ions, NH₄⁺.
In 4,50 moles are:
4.50 moles * 2 = 9.00 moles ammonium ions are present
which of the follwing is false ? A . the mass of proton is heavier than electron . B . protons and electron are found in nucleus C . Nucleus is very small but massive D . Neutrons are neutral particles
Answer:
C
Explanation:
The nucleus is very dense
A gas with a volume of 250 mL at a temperature of 293K is heated to 324K. What is the new volume of the gas?
V2 = 276 ml
Explanation:
Given:
V1 = 250 ml V2 = ?
T1 = 293K. T2 = 324K
Here, we use Charles's law:
V1/T1 = V2/T2
Solving for P2, we get
V2 = (T2/T1)V1
= (324K/293K)(250 ml)
= 276 ml