The weight for this compound is 74. what is the molecular formula
Explanation:
ur question is incomplete what elements make the compound and we talk of mass not weight and what are the units kjmol ,grams ,kgs
Is it posible Count a grain of sand?explain
Answer:
Yes
Explanation:
As long as its a solid, you can count it. It will be hard, but possible.
Which of the following is a metal?
a.
silicon, Si, Z = 14
b.
phosphorus, P, Z = 15
c.
thallium, Tl, Z = 81
d.
arsenic, Z = 33
e.
nitrogen, N, Z = 7
Answer:
A.................. I think the answer
3. Determine the enthalpy of formation for propane. 3C(s, gr) + 4H2(g) ---> C3H2(g) CzH3(g) AH = -2219.9 kJ C(s, gr) AH = -393.5 kJ H,(g) AH = -285.8 kJ a. -205.7 /mol b. -103.8 kJ/mol Å C. + 205.7 /mol d. + 103.8 /mol
Answer:
b I hope this is right good luck
What happens to the conductivity of water when a base is dissolved in it.
Answer:
See Explanation
Explanation:
The conductivity of water refers to how much it conducts electricity. The electrical conductivity of water increases as more ions are dissolved in it.
Hence, increase in concentration of dissolved ions improves the electrical conductivity of water.
Therefore, when a base (which is an ionic substance) is dissolved in water, the concentration of ions present increases and the conductivity of the solution increases accordingly since ions are charge carriers in solution.
The addition of a base to the sample results in an increase in the conductivity of the sample.
Conductivity can be defined as the transfer of charge by the sample. The sample has consisted of the ions that mediate the transfer of charge.
The sample with a high number of ions has consisted of high conductivity and vice versa. The dissolution of acid or base to the solution results in an increase in the number of ions in the solution, and thereby there has been an increase in the charge transfer.
Thus, with the increase in the charge transfer, there has been an increase in the conductivity of the sample.
For more information about the conductivity of the sample, refer to the link:
https://brainly.com/question/6072723
A 38.22 mL aliquot of weak acid that has a concentration of 0.882 M will be titrated with 0.289 M NaOH. Calculate the pH of of the solution upon neutralization of half of the weak acid. The Ka of the acid is 6.8×10-7.
Answer:
pH = 6.167
Explanation:
The weak acid, HX, reacts with NaOH as follows:
HX + NaOH → NaX + H₂O
Where 1 mole of HX with 1 mole of NaOH produce 1 mole of NaX (The conjugate base of the weak acid).
Now, using H-H equation:
pH = pKa + log [NaX] / [HX]
Where pH is the pH of the buffer
pKa is -log Ka = 6.167
And [NaX] [HX] are the molar concentrations of each specie
Now, at the neutralization of the half of HX, the other half is as NaX, that means:
[NaX] = [HX]
And:
pH = pKa + log [NaX] / [HX]
pH = 6.167 + log 1
pH = 6.167An analytical chemist is titrating 111.0 mL of a 0.3700 M solution of aniline (C6H5NH2) with a 0.3500 M solution of HNO3. The pK_b of aniline is 9.37. Calculate the pH of the base solution after the chemist has added 79.1 mL of the HNO_3 solution to it.
Answer:
The answer is "4.31"
Explanation:
aniline millimoles [tex]= 111 \times 0.37 = 41.07[/tex]
added [tex]HNO_3[/tex] millimoles [tex]= 79.1 \times 0.35 = 27.685[/tex]
[tex]\to 41.07 - 27.685 = 13.385[/tex] millimoles aniline left
[tex]\to 27.685[/tex] millimoles salt formed
total volume[tex]= 111 + 79.1 = 190.1\ mL\\\\[/tex]
[tex]\to [aniline] = \frac{13.385}{190.1} = 0.07 \ M\\\\\to [salt] =\frac{ 27.685}{ 190.1} = 0.146\ M\\\\\to pOH = pKb + \frac{\log [salt]}{ [base]}\\\\\to pOH = 9.37 + \frac{\log [0.146]}{[0.07]}\\\\\to pOH = 9.69\\\\\to pH = 14 - 9.69\\\\\to pH = 4.31\\[/tex]
Zn(s), Zn(NO3)2 (0.3 M) || Cu(s), CuCl2 (0.5 M)
(Need help solving these questions, so I can solve the rest of the questions like this in my lab. It is greatly appreciated. Thank you)
2. Write the half reactions that occur at the anode and cathode in this electrochemical cell. Annotate which half reaction occurs at the anode and the cathode.
3. Write the overall balance reaction of this electrochemical cell.
4. Calculate E°cell of this electrochemical cell. (include units)
5. Calculate the reaction quotient (Q) of this reaction.
6. Calculate the expected Ecell for this reaction
Answer:
See Explanation
Explanation:
At the anode;
Zn(s) -----> Zn^2+(aq) + 2e
At the cathode;
Cu^2+(aq) + 2e ------> Cu(s)
Overall electrochemical reaction;
Zn(s) + Cu^2+(aq) ------> Zn^2+(aq) + Cu(s)
E°cell = E°cathode - E°anode
E°cell = 0.34 - (-0.76)
E°cell = 1.1 V
Q = [0.3 M]/[0.5 M]
Q = 0.6
From Nernst equation;
Ecell = E°cell - 0.0592/n log Q
Ecell = 1.1 - 0.0592/2 log (0.6)
Ecell = 1.1 - 0.0296 log (0.6)
Ecell = 1.11 V
b) A piece of solid gold was heated from 274K to 314K using 55.7J of energy to raise the
temperature. What mass of gold was present?
Answer:
Explanation:
So we know q = mc[tex]\Delta[/tex]T.
q = 55.7 J
c = 0.129j/g°C
and [tex]\Delta[/tex]T = 314-274 = 40°C.
and m is mass which can solve since we got every other variable. We will get m = 10.8g.
I take in oxgyen from the air and send it into your bloodstream. I also remove the carbon dioxide from your body. What system am I?
muscular system
respiratory system
digestive system
skeletal system please help
water and Air are needed for iron rust answer true or false
Answer:True
Explanation:
PLZ GIVE ME BRAINLIEST, I NEED IT
Gelatinization happens with what type of Carbohydrate?
Coal, oil, and natural gas are called _______.
A.
fossil fuels
B.
renewable resources
C.
nuclear power
D.
solar energy
Answer:
I think it's A. I'm pretty sure.
Explanation:
Answer:
Coal, oil and natural gas are called _________A. fossil fuels
QUESTION 7
When excess magnesium was reacted with dilute sulphuric acid, the reaction was fast at first but
gradually became slower and finally stopped.
Which of the following describe the reaction?
A.
B.
The magnesium was used up.
The sulphuric acid was used up.
The temperature of the mixture decreased.
The magnesium particles became coated with hydrogen gas.
C.
D.
The reactant present in more amounts is called excess reagent. In the reaction between Mg and sulphuric acid, the reaction gradually stopped due to the consumption of the acid. Thus, option B is correct.
What is an excess reagent?An excess reagent is a chemical reactant present in more quantity than the other substance or reactant in the reaction. They are not totally consumed after the reaction ends, unlike the limiting reagent.
In the reaction, magnesium is the excess reagent while dilute sulphuric acid is a limiting reagent that determines the reaction rate and the product formation. At first, the reaction will be fast but gradually will become slow as all dilute sulphuric acid will be consumed slowing downs and stopping the reaction.
Therefore, dilute sulphuric acid will be used up at the end of the reaction.
Learn more about excess and limiting reagents here:
https://brainly.com/question/11848702
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please help me please
Answer:
Two advantages are: Its cheap and it is a renewable energy source. Two disadvantages are it's not windy everyday and it will take up a lot of space for windmills.
Explanation:
What is the correct coefficient for Fe2O3 in the balanced version of the following equation?
Fe2O3 + 3H2 → 2Fe + 3H2O
__Fe2O3+3H2→2Fe+3H2O
Answer:
The coefficient of Fe₂O₃ is 1
Explanation:
__Fe₂O₃ + 3H₂ —> 2Fe + 3H₂O
To know the correct coefficient of Fe₂O₃, we shall balanced the equation. This can be obtained as follow:
Fe₂O₃ + H₂ —> Fe + H₂O
There are 2 atoms of Fe on the left side and 1 atom on right side. It can be balance by writing 2 before Fe as shown below:
Fe₂O₃ + H₂ —> 2Fe + H₂O
There are 3 atoms of O on the left side and 1 atom on the right side. It can be balance by writing 3 before H₂O as shown below:
Fe₂O₃ + H₂ —> 2Fe + 3H₂O
There are 2 atoms of H on the left side and 6 atoms on the right side. It can be balance by writing 3 before H₂ as shown below:
Fe₂O₃ + 3H₂ —> 2Fe + 3H₂O
Now, the equation is balanced.
Thus, the coefficient of Fe₂O₃ is 1
Which ecosystem is the least stable?
A. A rain forest
B. A cornfield
C. A savanna
D. A coral reef
Calculate the pOH of this solution. pH = 1.90 pOH =
Answer:
12.1Explanation:
Since the pH has been given, the pOH can be found by using the formula
pH + pOH = 14
pOH = 14 - pH
From the question we have
pOH = 14 - 1.9
We have the final answer as
12.1Hope this helps you
Answer:
12.10
Explanation:
How many moles of argon gas would be present in a 37.0 liter vessel at 45.00 °C at a pressure of 2.50 atm?
Answer:
3.54 mol
Explanation:
Step 1: Given data
Volume (V): 37.0 LTemperature (T): 45.00 °CPressure (P): 2.50 atmStep 2: Convert "T" to Kelvin
We will use the following expression.
K = °C + 273.15
K = 45.00°C + 273.15 = 318.15 K
Step 3: Calculate the number of moles (n) of argon gas
We will use the ideal gas equation.
P × V = n × R × T
n = P × V/R × T
n = 2.50 atm × 37.0 L/(0.0821 atm.L/mol.K) × 318.15 K = 3.54 mol
Which is a correct comparison between the modern quantum model and John Dalton’s model of the atom?
Answer:
No comparison => John Dalton did NOT postulate an atomic structure.
Explanation:
Dalton's postulates are based upon generalizations of observable phenomena. Micro structure was not proposed. The atomic structure that's accepted in the scientific community evolved from conclusions of ...
Thompson's raisen pudding model => electrons suspended in a positive matrix
Rutherford's shell model => dense positive nucleus surrounded by an electron cloud. (No fine structure postulated)
Bohr Concentric Ring Model => electrons orbiting a positive nucleus in discrete energy levels much like planets orbiting the sun.
Schrodinger - Dirac Quantum Models => electrons occupying specific orbital energy levels as based upon statistical wave mechanics.
How many moles is 30 grams of CO2?
Answer:
68
Explanation:
does anyone know thisss???
How many molecules of O2 will be required to produce 28.8 g of water?
1.20×10−8s to nanoseconds
Answer:
There are 12 nanoseconds in [tex]1.2\times 10^{-8}\ s[/tex].
Explanation:
We need to convert [tex]1.2\times 10^{-8}\ s[/tex] to nanoseconds.
We know that,
[tex]1\ s=10^9\ ns[/tex]
Now using unitary method to solve it such that,
[tex]1.2\times 10^{-8}\ s=1.2\times 10^{-8}\ \times 10^9\\\\=1.2\times 10\\\\=12\ ns[/tex]
So, there are 12 nanoseconds in [tex]1.2\times 10^{-8}\ s[/tex].
Chrysanthemic acid occurs as a mixture of esters in flowers of the chrysanthemum (pyrethrum) family.
a. True
b. False
Answer:
A: True
Explanation:
Statement is true because chrysanthemic acid is formed naturally as a result of production of two molecules of dimethylallyl diphosphate which forms pyrophosphate ester.
Thus, it belongs to the pyrethrum family
Question 6 of 30 Carbon dioxide subliming is an example of which of the following?
Answer:
dry ice or solid carbon(iv)oxide
Explanation:
carbon(iv)oxide that sublimes is known as dry ice or solid CO2 and it is used to refrigerate food instead of ordinary ice which will just melt when exposed to hot conditions and there4 will lead to the destruction of food. dry ice will sublime the moisture from the food there4 keeping out any moisture
Give an example of a model used in Earth science. Explain why models are particularly important to this field.
Answer:
Some examples include maps and globes. Conceptual Models - These models serve as a tool to piece together a variety of concepts together so that we can better conceptualize the phenomena under investigation.
Scientific models are used to explain and predict the behaviour of real objects or systems and are used in a variety of scientific disciplines, ranging from physics and chemistry to ecology and the Earth sciences
Addition of sugar to water will result in increase of boiling point
TRUE OR FALSE
Answer:
true
Explanation:
25m
45m
Help pls.........
Answer:
45m
Explanation:
The molecular weight (MW) of CuSO4 is 250g/mol. How many grams of CuSO4 are needed to make a 10 ml solution that has a molarity of 2.0 M?
Answer:
Explanation:
(The MW of CuSO4 is 250 g/mol).
Answer:
5 grams of CuSO4
Explanation:
First you make a stoichiometric relationship between the molarity and liters. So there is 2 mols per every liter. Then you put in the moleculur weight( for every mol there is 250 g). Then you have to get rid of the liters, so you times the equation by 0.01(this was found by 10ml converted into liters). After all of that you should end up with 5 grams of CuSo4