Answer:
Molality of solution=10.11 m
Explanation:
We are given that
Given mass of KCl(WB)=75.3 g
Given mass of water (WA)=100 g=100/1000=0.1 kg
1 kg=1000 g
Molar mass of H=1.01 g
Molar mass of K=39g
Molar mass of Cl=35.45 g
We have to find the molality of a solution.
Molar mass of KCl(MB)=39+35.45
Molar mass of KCl(MB) =74.45 g
Number of moles of solute (KCl)=[tex]\frac{given\;mass}{molar\;mass}=\frac{W_B}{M_B}[/tex]
Number of moles of solute (KCl)=[tex]\frac{75.3}{74.45}[/tex]
Number of moles of solute (KCl)=1.011 moles
Molality of solution
=[tex]\frac{number\;of\;moles\;of\;solute}{mass\;of\;solvent}[/tex]
Using the formula
Molality of solution=[tex]\frac{1.011}{0.1}[/tex]
Molality of solution=10.11 m
How many grams of caffeine should we prepare in a 10 mL standard of 3 mm
a) 0.05 grams
b) 2.57 grams
c) 0.00583 grams
d) 5 grams
PLEASE HELP!
Answer:
if it is espresso(1 shot), the coffee content to be considered is: (77/44)*(10/3)= 5.833= 0.005833 grams
Explanation:
Chemical A breaks down into chemical B. At t=0, [A] = 0.100 M. At t=10.0 s, [A] = 0.075 M. What is the average reaction rate?
Answer:
a0.0075 mi i think so ok but average is need to add and divide
which atom has the highest ionization energy? magnesium, barium, calcium, beryllium
Explanation:
Beryllium has the highest Ionization energy
A gas has an initial pressure of 120 kPa, a volume of 23 liters, and a temperature of 20°C. If the pressure is raised to 150 kPa the new volume is 17 liters, what is the new temperature of the gas? *
A.100 K
B.0.003 K
C.270.7 K
D.18.4 K
If your end product is 1.5 moles of KMnO4, how many moles of manganese oxide were used in the reaction?
The equation for the production of potassium permanganate is as follows:
2 MnO2 + 4 KOH + O2 → 2 KMnO4 + 2 KOH + H2
You must show all work
Answer:
1.5 moles of KMnO4 will be produced from 1.5 moles of MnO2
Explanation:
The balanced equation of this chemical reaction is
2 MnO2 + 4 KOH + O2 → 2 KMnO4 + 2 KOH + H2
2 moles of MnO2 produces 2 moles of KMnO4
That means 1 moles of KMnO4 will be produced from 1 moles of MnO2
Hence, 1.5 moles of KMnO4 will be produced from 1.5 moles of MnO2
The moles of manganese oxide were used in the reaction is 1.5 moles.
What is stoichiometry?Stoichiometry of any reaction tells about the relative amount of species present before and after the chemical reaction.
Given chemical reaction is:
2MnO₂ + 4KOH + O₂ → 2KMnO₄ + 2KOH + H₂
From the stoichiometry of the reaction, it is clear that same moles of manganese oxide and potassium permanganate is involved in the reaction.
2 moles of KMnO₄ = produce by 2 moles of MnO₂
1.5 moles of KMnO₄ = produce by 2/2×1.5=1.5 moles of MnO₂
Hence, required moles are 1.5 moles.
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An isotope undergoes radioactive decay. The new isotope that forms has an atomic number that is 2 less than the original isotope’s.
Which kind of decay has occurred, and how do you know?
1)alpha decay because alpha particles have a large mass
2)beta decay because beta particles can have negative charge
3)alpha decay because alpha particles have two protons and two neutrons
4)gamma decay because gamma rays are photons
Answer:
3)alpha decay because alpha particles have two protons and two neutrons
Explanation:
When a radioactive isotope undergoes a decay, a daughter nucleus or nuclei is/are formed. The mass number and atomic number of the daughter nucleus gives us an idea of the nature of radioactive decay that the parent nucleus underwent.
If the daughter mass number of the daughter nucleus is four units less than that of the parent nucleus and the atomic number of the daughter nucleus is two units less than that of the parent, then such a decay is an alpha decay.
An alpha particle has two protons and two neutrons thus it has a mass number of 4 and an atomic number of two.
Energy that is made from the power of moving water
a
b
ОООО
wind
hydroelectric
coal
с
d
biomass
Hydroelectric energy is produced.
Someone please help me
Answer:reflection
Explanation:
What type of reaction is Al + KOH +H2O = K[Al(OH)4] + H2
Answer:
Al + 2 KOH + 6 H 2O → 3 H 2 + 2 K[Al(OH) 4] This is a complexation reaction: K[Al(OH) 4] is the formed complex. ; Silvery-white, malleable, ductile, odorless metal.
Explanation:
I hope this help
chemical formula for diethyl ester dimethyl ammonium chloride
-PLEASE HELP ASAP
I NEED HELP WITH CHEM PLEASE HAVE A DECENT ANSWER
Answer:
x is HCl because pH = 2 (acid and it reacted with Mg plus it turned litmus paper to red)
y is NaOH because pH = 10 (base and turned litmus paper to blue)
z is NaCl because pH = 7 (neutral and no reaction to litmus paper and Mg)
A Cartesian Diver demonstrates which of the following?
A. the inverse relationship of Boyle's law
B. the direct relationship of Boyle's law
C. squeezing the bottle, pushes the test tube down.
D. the density of a gas is less than the density of water.
Answer:
(a) The inverse relationship of Boyle's law.
Explanation:
A Cartesian diver is used in scientific experiments to demonstrate the certain principles in science such as;
i. The principle of floatation or the Archimedes' principle.
ii. The implication of the ideal gas law as seen in, for example, Boyle's law and pressure law,
iii. Pascal's principle.
The diver demonstrates that given a large soft drink bottle containing water and a medicine dropper at its top, squeezing the bottle pushes the dropper down to the bottom. When the squeezing stops, the dropper comes back to the top again.
Now using this to demonstrate Boyle's law (which shows the relationship between pressure and volume where increase in one results in the decrease in the other), when the bottle is squeezed (which means pressure is increased on the bottle), the water is forced into the medicine dropper thereby decreasing the volume of air in the dropper. Removing pressure on the bottle produces an opposite effect.
CaCl2
Ca +
CI2
Balance this equation
To balance Ca + Cl2 = CaCl2 you'll need to be sure to count all of atoms on each side of the chemical equation.
Once you know how many of each type of atom you can only change the coefficients (the numbers in front of atoms or compounds) to balance the equation for Calcium + Chlorine gas.
Use an example of how we use an informal kind of scientific method in our everyday lives
Answer:
baking cookies
Explanation:
One example of using a scientific method is baking cookies. You make a hypothesis that you cookies will be done in 15 minutes. Then, after 15 minutes, you see that either your hypothesis was correct and you cookies are perfect or you need to bake them longer making you hypothesis incorrect. (please change the wording up a bit if you want. i tried to make it make the most sense)
Answer:
Explanation:
When you loose your phone. You try to remember where you last used your phone, and question yourself where you might have left it. If you say that you probably left it in the kitchen, that would be like your hypothesis. Then you go look for it where you thought you left it which would be your experiment. If maybe it is not there that would be like your conclusion so you would reject your hypothesis because it was wrong. Then you try the scientific method again but with a different hypothesis, like that maybe you left it in the living room. You do your experiment which is when you go look for it. In the conclusion if your hypothesis was right you accept your hypothesis. That can be an example of how we use the scientific method in our everyday lives.
How many elements in a periodic table?
How many moles of sulfur S, will react with six moles of aluminum?
Answer:
9 moles of Sulphur will react with 6moles of Aluminum
Why is it useful to know the background level of extinction?
It is part of the scientific process to observe changes in nature.
If current rates greatly exceed background rates, scientists say there is a chance of a
mass extinction event happening.
NOAA and FWS are required by law to compare background rates to current rates.
Scientists want to see if increased extinction rates will threaten the human population.
Answer:
NOAA and FWS are required by law to compare background rates to current rates.
Explanation:
Answer:
If current rates greatly exceed background rates, scientists say there is a chance of a mass extinction event happening.
Explanation:
Scientists compare current rates of extinction to the background rate to see if there is a potential problem developing.
I got it right on the quiz.
The ____ allows you to compare the elements and understand their properties
Answer:
Periodic Table
hope this helps
have a good day :)
Explanation:
The periodic table allows you to compare the elements and understand their properties.
What is periodic table?Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.
It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.
Elements present in the same group have same number of valence electrons and hence have similar properties while elements present in the same period show gradual variation in properties due to addition of one electron for each successive element in a period.
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Which of the following best describes density?
- the relationship between length and mass
- the relationship between volume and area
- the relationship between mass and area
- the relationship between mass and volume
Answer:
the relationship between mass and volume
If hydrochloric acid is obtained commercially at a concentration of 12.1M, how many milliliters of 12.1M HCl(aq) must be used to prepare 2.00x103mL of 0.500M HCL(aq)?
Answer:
[tex]V_1=82.6mL[/tex]
Explanation:
Hello there!
In this case, according to this question, we will need to deal with this dilution problem, because it is asking for the volume of a 12.1-M stock solution of HCl. In such a way, we can use the following equation, under the assumption of no change in the number of moles in the solution:
[tex]M_2V_2=M_1V_1[/tex]
Thus, we solve for the initial volume, V1, as shown below:
[tex]V_1=\frac{M_2V_2}{M_1}[/tex]
And plug in the initial concentration and final concentration and volume to obtain:
[tex]V_1=\frac{2000mL*0.500M}{12.1M}\\\\V_1=82.6mL[/tex]
Regards!
The combustion of acetylene gas is represented by this equation: 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g)
How many moles of H2O are produced when 64.0 g C2H2 burn in oxygen?
M.M
H2O = 18.02 g/mol
C2H2 = 26.04 g/mol
2.46 moles H2O
5.13 moles H2O
4.92 moles H2O
2.00 moles H2O
Answer:
Approximately [tex]2.46\; \rm mol[/tex].
Explanation:
Make use of the molar mass data ([tex]M({\rm C_2H_2}) = 26.04\; \rm g \cdot mol^{-1}[/tex]) to calculate the number of moles of molecules in that [tex]64.0\; \rm g[/tex] of [tex]\rm C_2H_2[/tex]:
[tex]\begin{aligned}n({\rm C_2H_2}) &= \frac{m({\rm C_2H_2})}{M} \\ &= \frac{64.0\; \rm g}{26.04\; \rm g\cdot mol^{-1}}\approx 2.46\; \rm mol\end{aligned}[/tex].
Make sure that the equation for this reaction is balanced.
Coefficient of [tex]\rm C_2H_2[/tex] in this equation: [tex]2[/tex].
Coefficient of [tex]\rm H_2O[/tex] in this equation: [tex]2[/tex].
In other words, for every two moles of [tex]\rm C_2H_2[/tex] that this reaction consumes, two moles of [tex]\rm H_2O[/tex] would be produced.
Equivalently, for every mole of [tex]\rm C_2H_2[/tex] that this reaction consumes, one mole of [tex]\rm H_2O[/tex] would be produced.
Hence the ratio: [tex]\displaystyle \frac{n({\rm H_2O})}{n({\rm C_2H_2})} = \frac{2}{2} = 1[/tex].
Apply this ratio to find the number of moles of [tex]\rm H_2O[/tex] that this reaction would have produced:
[tex]\begin{aligned}n({\rm H_2O}) &= n({\rm C_2H_2}) \cdot \frac{n({\rm H_2O})}{n({\rm C_2H_2})} \\ &\approx 2.46\; \rm mol \times 1 = 2.46\; \rm mol\end{aligned}[/tex].
The concentration of a reactant dropped from 1M to 0.6 Min 15 seconds.
Calculate the reaction rate of this reaction in M/min.
Answer:
1.6 M/min
Explanation:
Step 1: Given data
Initial concentration of the reactant: 1 MFinal concentration of the reactant: 0.6 MTime elapsed (t): 15 sStep 2: Convert "t" to min
We will use the conversion factor 1 min = 60 s.
15 s × 1 min/60 s = 0.25 min
Step 3: Calculate the reaction rate
We will use the following expression.
r = -ΔC/t
r = -(0.6 M - 1 M)/0.25 min = 1.6 M/min
What is diffusion? How does the motion of gas molecules explain how a gas diffuses throughout a room?
Answer:
Diffusion in gases
Diffusion is driven by differences in concentration. When chemical substances such as perfume are let loose in a room, their particles mix with the particles of air. The particles of smelly gas are free to move quickly in all directions
Explanation:
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How do I calculate the pOH of a Solution at 25℃ with a [OH-1] = 6.5 x 10-9 M and state whether the Solution is Acidic, Basic, or Neutral?
Answer:
pOH = 8.19
Acidic solution (pH < 7.0)
Explanation:
The pOH of the solution is defined as:
pOH = - log [OH⁻]
Since we have [OH⁻] = 6.5 x 10⁻⁹ M, we calculate the pOH as follows:
pOH = - log (6.5 x 10⁻⁹) = 8.19
To know if the solution is acidic, neutral or basic, we have to calculate the pH from the value of pOH:
pH + pOH = 14
⇒ pH = 14 - pOH = 14 - 8.19 = 5.81
The solution is acidic because pH < 7.0.
6 a 100 sample of Au - 198 Au 198 be? Decays to 3.125 g in 13.5 days, what would the half-life of au198 be?
Answer:
Half-life = 2.7 days
Explanation:
The radioactive decay of an isotope follows the equation:
Ln[A] = -kt + ln[A]₀
Where [A] could be taken as the amount of A after t time, k is decay constant, [A]₀ initial amount of A.
Replacing to solve k:
Ln[3.125g] = -k*13.5days + ln[100g]
-3.465736 = -k*13.5days
k = 0.2567days⁻¹
Half-life is:
half-life = ln2 / k
Half-life = 2.7 days
A gas' pressure is 850 torr at 47 degrees. At what temperature will the pressure be 655 torr?
Answer:
From Pressure Law
P1/T1 = P2/T2
Changing our temp to kelvin
T1 = 47 +273 = 320K
We're looking for T2
Making T2 the subject
T2 =P2 x T1 / P1
= 655 x 320/850
T2 = 246K
Molar mass of propan-1-ol
Answer:
60g/mol.
Explanation:
TO FIND :-
Molar mass of Propan-1-olFACTS TO KNOW BEFORE FINDING ANSWER :-
Chemical formula of Propan-1-ol = CH₃CH₂CH₂OH [or] C₃H₈OMolar mass of C = 12g/mol.Molar mass of H = 1g/mol.Molar mass of O = 16g/mol.SOLUTION :-
Molar mass of C₃H₈O = 3(Molar mass of C) + 8(Molar mass of H) + 1(Molar mass of O)
⇒ Molar mass of C₃H₈O = (3×12) + (8×1) + 16 = 36 + 8 + 16 = 60g/mol.
Which of the following MOST LIKELY causes the rate of a chemical reaction to increase?
Decreasing the reaction temperature
Grinding up a solid reactant
Adding an inhibitor
Using a larger container
Explanation:
Reactant concentration.
Increasing the concentration of one or more reactants will often increase the rate of reaction. This occurs because a higher concentration of a reactant will lead to more collisions of that reactant in a specific time period.
A pan containing 20.0 grams of water was allowed to cool from a temperature of 95.0 °C. If the amount of heat released is 1,200 joules, what is the approximate final temperature of the water? (5 points)
75 °C
78 °C
81 °C
87 °C
Answer:
78° C.
Explanation:
The final temperature of water is 81℃ , if it is allowed to cool from a temperature of 95 and it releases heat of 1200J.
What is the final temperature of water?In the following question we will apply specific heat Capacity equation
q=mct Δt
q= 1200J m= 20 g c= 4.186 T₁= 95 ℃
1200= 20 ✕4.186(95-T₂)
T₂=81℃
Hence, The water cools to 81℃ temperature
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I have to do this for homework please help :)
Answer:
1..... nucleus
2......electron cloud
3.......protons
4........Neutrons
5..........electron
6............electrons
7...............Isotopes
8.....,...........ions
9....................charge