Answer:
Gases, liquids and solids are all made up of microscopic particles, but the behaviors of these particles differ in the three phases. Gas are well separated with no regular arrangement. liquid are close together with no regular arrangement. solid are tightly packed, usually in a regular pattern.
Explanation:
Consider two compounds. Compound A contains 15.7 g of sulfur and 18.6 g of fluorine. Compound B contains 25.4 g of sulfur and 60.2 g of fluorine. For Compound A, the ratio of fluorine to sulfur is 1.18. For Compound B, the ratio of fluorine to sulfur is 2.37. Using the Law of Definite Proportions (also called the Law of Constant Composition), could Compound A and Compound B be the same compound
Answer:
No, compound A and B are not the same compound
Explanation:
According to the law of definite proportion "every chemical compound contains fixed and constant proportions (by mass) of its constituent elements." (Encyclopedia Britannica)
We can see in the question that the ratio of flourine to sulphur in compound A is 1.18 while the ratio of flourine to sulphur in compound B is 2.37.
The two chemical compounds do not contain a fixed proportion by mass of their constituent elements therefore, they can not be same compound according to the law of definite proportions.
If the mercury in a manometer raises 30.0 millimeters due to a change in pressure, what is the corresponding change in pressure in atm?
Answer:
0.03947 atm
Explanation:
The relationship between mmHg and atm is given as;
1 atm = 760 mmHg
x atm = 30 mmHg
Upon solving for x;
x * 760 = 30 * 1
x = 30 / 760 = 0.03947 atm
The map shows the average high temperatures in July for two cities in Texas.
Average July High Temperatures
Texas
Del Rio
36°C
Galveston
32°C 12
Answer:
Highest temperature which was recorded in Texas was 40 degrees.
Explanation:
Texas has variating weather. In summer Texas city turns to be very hot and during winters the city of Texas experience fall in temperature. There is very few rainfall in Texas due the climatic conditions.
What do atoms make up
(04.02 LC)
During photosynthesis, water and carbon dioxide become glucose and oxygen.
True
False
Answer:
true............,....
Answer:False
Explanation:
This statement is false. Correct statement: Photosynthesis produces glucose and oxygen. ... In this process, plants produce glucose and oxygen from carbon dioxide and water in the presence of sunlight. Photosynthesis converts light energy into chemical energy.
Fred is about to order a stack of four pancakes with butter and syrup, but he wonders how much he would need to exercise to burn off the Calories from it. He pulls out his cell phone and finds the nutritional information for the stack of pancakes. He notes that a serving has 181g of carbohydrates, 27g of fat, and 16g of protein. Now, he has to convert these values into Calories.
Running at a pace of 8 minutes per mile burns 14 Calories/minute. How many minutes would he have to run at an 8 minutes per mile pace to bum off the Calories from the stack of pancakes?
Answer:
The correct answer is - 73.64 minutes.
Explanation:
We know that each gram of protein and carbohydrate produces 4 calories of energy whereas fat produces 9 cal energy per gram.
So, the Calories from carbohydrates
= 181 ×4
= 724 Cal
and, 27 g fat produces = 27 × 9 = 243 Cal
and, 16 g protien = 16 × 4 = 64 Cal
so the total energy will be - 243+ 724+ 64 = 1031 Cal
Thus, the time Fred need to run = 1031/14 =73.64 min
What is the volume of 3.5 moles of carbon dioxide (CO2) gas at STP?
0 6.40 |
0.16 L
0 78.4 L
Cannot be determined from the information given
Answer:
78.4
Explanation:
3. Which state of matter has a defined shape?
HELP FAST
Answer:
Solid state of matter has a definite shapeThe answer to this is solids!
1. The equation for the reaction between zinc and aqueous copper(II) sulfate is shown.
Zn + Cuso, → ZnSO, + Cu
Which statement is correct?
a. The oxidation state of the oxidising agent has changed from 0 to +2.
b. The oxidation state of the reducing agent has changed from 0 to +2.
c. The oxidation state of the reducing agent has changed from +2 to 0
d. This is not a redox reaction. The solution changes from colourless to blue.
Answer:
The oxidation state of the reducing agent has changed from 0 to +2.
Explanation:
reducing agent is anything that loses electron or gains oxygen
in this case, zinc
Which is mainly responsible for preventing erosion?
A) Mining
B) Farming
c) Rooting of Plants
D) Logging
Answer:
B. Farming
Explanation:
which one of the following are pure substances : water,salt water,copper,brass,air,oxygen
Answer:
Copper, Water, and Oxygen
Explanation:
Because they are compounds and compounds are pure substances <3
Answer: copper
Explanation: because all of the atoms that make up copper are copper i.e its not a compound or mixture. not made od molecules
A 150.0mL sample of an aqueous solution at 25C contains 15.2mg of an unknown nonelectrolyte compound. If the solution has an osmotic pressure of 8.44 torr, what is the molar mass of the unknown compound?
Answer:
MM = 225.11 g/mol
Explanation:
In this case, let's analyze the data.
We have a 15.2 mg of an unknown electrolyte in 150 mL of solution. The osmotic pressure is 8.44 Torr, and we want the molecular mass of the unknown.
The osmotic pressure can be calculated using the following expression:
π = CRT (1)
π: osmotic pressure (8.44 Torr * 1 atm / 760 Torr = 0.011 atm)
C: Concentration of the unknown in the solution
R: universal constant of gases (0.082 L atm / K mol)
T: temperature in Kelvin (25 + 273 = 298 K)
From this expression, we can either solve for C, and then use another expression to calculate the molecular mass, or we can just replace the expressions in the above formula, to get the direct molecular mass. In this case, we'll follow the second method.
Concentration or molarity of a substance can be calculated using:
C = moles / V (2)
And moles can be calculated using this expression:
moles = m / MM (3)
Replacing (3) in (2), and then in (1) we have:
C = m / MM * V
π = m * RT / MM * V (4)
and now, we can solve for MM:
MM = mRT / π V (5)
Now, we just need to replace the given data into the above expression to get the value of the molecular mass:
MM = (15.2 / 1000) * 0.082 * 298 / 0.011 * 0.150
MM = 225.11 g/molHope this helps
Blank is ____ rock in molten form
What is this please help
Answer:
Rock In molten form is Lava
^_^
name the following compounds TeF4
Answer:
Tellurium Fluoride
Explanation:
Methyl isocyanate, shown as resonance structure 1, can also be represented by other resonance structures. Draw the next most important resonance contributor. Then add curved arrows to each structure to show delocalization of electron pairs to form the other structure.
Include lone pairs of electrons, formal charges, and hydrogen atoms. You can add condensed hydrogens using the More menu, selecting +H and clicking on the carbon as many times as needed.
Solution :
Structure I
The formal charge on both Carbon (C) atom is = 4 valance [tex]$e^-$[/tex] - bonds = 0
Formal charge (O) = 6 V.E - 2 bonds - 4 non bonding electrons = 0
Formal charge on (N) = 5 V.E - 3 bonds - 2 non bonding electrons = 0
F.C. on H = 1 V.E. - 1 bond = 0
Overall charge on the molecule = 0 charge
Structure II
Formal charge on both C atom = 4 valence [tex]$e^-$[/tex] - 4 bonds = 0
Formal charge (O) = 6 V.E. - 1 bonds - 6 non bonding electrons = -1 charge
Formal charge on (N) = 5 V.E. - 4bonds - 0 non bonding electrons = +1 charge
F.C on H = 1 V.E. - 1 bond = 0
Overall charge on the molecule = +1 -1
= 0 charge
What is the pH of a solution with a H+ ion of 2×10-¹²?
Answer:
11.7
Explanation:
The pH is the negative logarithm of the concentration of H+ ions. If the concentration is 2×10-¹² the the pH will be -log(2×10-¹²) which is 11.698 which can be round up to 11.7.
Observe: Click Reset. Select the Gas collection setup. Chemists use this apparatus to collect any gases produced in the reaction. From the reaction flask, gases travel through a long tube and into a cylinder of water. As gases bubble into the cylinder, the water is displaced (removed) until the cylinder is filled with gas. Was any gas produced in the reaction? How do you know? I WILL GIVE POINTS AND BRAINLIEST IF YOU ANSWER CORRECTLY. THANK YOU :)
Answer:
Due to displacement of water.
Explanation:
If the water is displaced in the cylinder it means that the gas is produced in the reaction while on the other hand, if the water is not displaced in the cylinder so it means that the reaction does not produces any gas yet. So we can say that the displacement of waters indicates or shows us whether the gas is produced in the reaction or not.
how can i balance Na + Ca2+ --> Ca + Na+
Answer:
[tex]2Na + Ca^{2+} \rightarrow Ca + 2Na^+[/tex]
Explanation:
Hello!
In this case, since this a reaction in which the oxidation state of the metals is changing, we need to apply a redox method for which:
[tex]Na\rightarrow Na^++e^-\\\\Ca^{2+}\rightarrow Ca+2e^-\\\\\\2Na\rightarrow 2Na^++2e^-\\\\Ca^{2+}\rightarrow Ca+2e^-[/tex]
Thus, the result is:
[tex]2Na + Ca^{2+} \rightarrow Ca + 2Na^+[/tex]
Regards!
17. Which of the following statement best explains what pollination is?
A. It is the union of sperm and egg cell.
B. It is the process where the pollen of one flower reaches the stigma of another flower.
C. It is the process wherein plants are developed from seeds.
D. It is the process by which seeds are sent by their parent plant into a faraway place to
become a new plant.
Answer:
ıt is the projesi where the polen of one flower reaches the sığmaz of another flower.
Answer:
B
Explanation:
Have a nice day☺gsjsjamsvwksk
I have calculated 23 grams of water in a laboratory. What is the amount of molecules
present in this amount?
a. None of the above
b. 8.3x10^24 molecules
c. 6.9x10^23 molecules
d. 7.7x10^23 molecules
e. 5.6x10^25 molecules
Answer:
d. 7.7x10^23 molecules
Explanation:
Given the following data:
Mass of water (H2O) = 23g
To find the number of molecules;
First of all, we would determine the number of moles;
[tex] Number \; of \; moles = \frac {mass}{molar mass} [/tex]
Molar mass of water (H2O) = (1 * 2) + 16 = 18 g/mol
Substituting into the equation, we have
[tex] Number \; of \; moles = \frac {23}{18} [/tex]
Number of moles = 1.2778 moles
Now, to find the number of water molecules;
We know that Avogadro constant is equal to 6.02 * 10^23 mol¯¹
Number of water molecules = number of H2O moles * Avogadro constant
Substituting into the equation, we have;
Number of water molecules = 1.2778 × 6.02 * 10^23
Number of water molecules = 7.7 × 10^23 atoms.
what is the smallest substance?
1 .mixture
2 .compound
3 .element
Look at sample problem 19.5 in the 8th ed Silberberg book. Write the ion-product expression at equilibrium for each compound: How to enter the correct answer: e.g. silver sulfate (Ag2SO4) enter this: {Ag+}2{SO42-} don't enter spaces, use square brackets [] not{}or () for concentration and don't worry about subscripting or superscripting
(1) magnesium carbonate
(2) calcium phosphate
(3) silver sulfide
Answer:
See explanation
Explanation:
The term ion product is an expression that does not necessarily reflect equilibrium conditions which can be used to determine the concentration of ions in a solution of the stated substance. As a matter of fact, the ion product is different from the solubility product which reflects equilibrium conditions.
The ion product of the following substances are shown below;
magnesium carbonate - MgCO3
MgCO3(aq) -------> [Mg^2+] [CO3^2-]
calcium phosphate - Ca3(PO4)2
Ca3(PO4)2(aq) --------> [Ca^2+]^3 [PO4^3-]^2
silver sulfide - Ag2S
Ag2S(aq) --------> [Ag^+]^2 [S^2-]
Determine whether each observation generally corresponds to a physical change or a chemical change. A liquid freezes into a solid. _________ Bubbles are produced upon mixing two solutions. __________ A precipitate is formed from two solutions. _________ A solution heats up upon mixing with another. ____________ A solid dissolves into water. __________ The color of a substance changes over time
Answer:
A liquid freezes into a solid or any other state change is a physical change. Bubbles are produced upon mixing two solutions is a Chemical change as gas formed. a precipitate is formed from two solutions is a Chemical change The conversion of a substance to another compound over time leads to a color change of the substance due to the insolubility of the compound.
It is a chemical change or properties. A solution that heats up upon mixing with another is a Chemical change known as an exothermic reaction. dissolving the substance in a liquid is a physical change physical that can be regained by evaporation or crystalization.
A chemistry student is given 650. mL of a clear aqueous solution at 33.°C. He is told an unknown amount of a certain compound X is dissolved in the solution. The student allows the solution to cool to 17.9 0C. At that point, the student sees that a precipitate has formed. He pours off the remaining liquid solution, throws away the precipitates, and evaporates the water from the remaining liquid solution under vacuum. More precipitate forms. The student washes, dries and weighs the additional precipitate. It weighs 0.150 kg.
1. Using only the information above, can you calculate the solubility of X in water at 17 0C.
2. If you said yes, calculate it.
Answer:
No, you can not calculate the solubility of X in water at 17 0C.
Explanation:
Solubility refers to the amount of a substance that dissolves in 1000 L of water.
To calculate the solubility of a solute in water, all the water is evaporated and the solid is carefully collected, washed, dried and weighed. The mass of solid obtained can now be used to calculate the solubility of the solute in water as long as there was no loss in mass of solid during the experiment.
In this case, the student threw away part of the solid that precipitated. As a result of this, the mass of solid obtained at the end of the experiment is not exactly the total mass of solute that dissolved in the solvent. Hence, the solubility of X in water at 17 0C can not be accurately calculated.
A tank contains 10 liters of pure water. A solution of an unknown, but constant concentration of salt is flowing in at 0.5 liters per minute. The water is mixed well and drained at 1 liter per minute. After 20 minutes there are 10 grams of salt in the tank. (i) Give an adequate mathematical model for this scenario. Explain what each of your variables means. (ii) What is the concentration of the incoming salt solution
Answer:
i) ∴∫[tex]\frac{dA}{A}[/tex] = ∫ [tex]\frac{-1}{10} dt[/tex] ------ ( 1 )
ii) C = 4.303
Explanation:
Given data:
water in tank = 10 liters
concentration of salt flowing in = 0.5 liters/min
10 grams of salt is left in tank after 20 minutes
mixed water is drained at 1 liter per minute
i) Adequate mathematical model for the scenario
lets assume ; A( t ) amount of salt after t minute
A( t ) = 10grams where t = 20 minutes
differentiate A(t)
dA / dt = ( rate in ) - ( rate out )
= 0.5 * 0 - A/10
∴∫[tex]\frac{dA}{A}[/tex] = ∫ [tex]\frac{-1}{10} dt[/tex] ------ ( 1 )
ii) hence; In A = [tex]\frac{-1}{10} t + C[/tex] ----- ( 2 )
at t = 20 , A = 10grams
find C = In 10 + 2
= 2.303 + 2 = 4.303
back to ( 2 )
In A = [tex]\frac{-t}{10} + 4.303[/tex]
∴ A = e [tex]\frac{-t}{10} + 4.303[/tex]
A 0.90 g of hydrogen chloride (HCl) is dissolved in water to make 5.0 L of solution. What is the pH of the resulting hydrochloric acid solution?
Express the pH numerically to two decimal places.
0.50g of sodium hydroxide (NaOH) pellets are dissolved in water to make 4.0L of solution. What is the pH of this solution?
Express the pH numerically to two decimal places.
Answer:
Explanation:
Mol weight of HCl = 36.5
.90 g of HCl = .90 / 36.5 mole = .02465 mole
HCl = H⁺ + Cl⁻
1 mole 1 mole
1 mole of HCl gives 1 mole of H⁺
.02465 mole of HCl will give .02465 mole of H⁺
.02465 mole of H⁺ in 5 litre soln
concentration of H⁺ = .02465 / 5 = 4.93 x 10⁻³ M
pH = - log ( 4.93 x 10⁻³ )
= 3 - log 4.93
= 3 - .693
= 2.307
= 2.31
NaOH :
Mol weight of NaOH = 40
.50 g of HCl = .50 / 40 mole = .0125 mole
NaOH = Na⁺ + OH⁻
1 mole 1 mole
1 mole of NaOH gives 1 mole of OH⁻
.0125 mole of NaOH will give .0125 mole of OH⁻
.0125 mole of OH⁻ in 4 litre soln
concentration of OH⁻ = .0125 / 4 = 3.125 x 10⁻³ M
pOH = - log ( 3.125 x 10⁻³ )
= 3 - log 3.125
= 3 - .495
= 2.505
pH = 14 - pOH
= 14 - 2.505
= 11.495 .
= 11.50
I need help answering number 14 A B and C. Thank you!
Answer:
Explanation:
TiO2 + C + 2 CI2 → TiCI4 + CO2
(a)
(2.16 mol TiO2) x (2 mol CI2 / 1 mol TiO2) x ( 70.9064 g C/mol) = 306 g CI2
(b)
(2.16 mol TIO2) x (1 mol C / 1 mol TiO2) x ( 12.01078 g C/mol)n= 25.9 g C
(c)
Use the law of conservation of mass:
(2.16 mol TiO2) x ( 79.8660 g TiO2/mol) + (306 g CI2 + 25.9 g C = 504 g total.
Hope this help!:)
Heart attacks can cause sudden death.
True
False
Answer:
True
Explanation:
A chemist titrates 190.0 mL of a 0.8125 M ammonia (NH) solution with 0.3733 M HCl solution at 25 °C. Calculate the pH at equivalence. The pK, of
ammonia is 4.75.
Round your answer to 2 decimal places.
Note for advanced students: you may assume the total volume of the solution equals the initial volume plus the volume of HCl solution added.
pH ?
Answer:
Approximately [tex]4.92[/tex].
Explanation:
Initial volume of the solution: [tex]V = 190.0\; \rm mL = 0.1900\; \rm L[/tex].
Initial quantity of [tex]\rm NH_3[/tex]:
[tex]\begin{aligned} n({\rm NH_3}) &= c({\rm NH_3}) \cdot V({\rm NH_3}) \\ &= 0.3733\; \rm mol \cdot L^{-1} \times 0.1900\; \rm L \\ &\approx 0.154375\; \rm mol\end{aligned}[/tex].
Ammonia [tex]\rm NH_3[/tex] reacts with hydrochloric [tex]\rm HCl[/tex] acid at a one-to-one ratio:
[tex]\rm NH_3 + HCl \to NH_4 Cl[/tex].
Hence, approximately [tex]n({\rm HCl}) = 0.154375\; \rm mol[/tex] of [tex]\rm HCl\![/tex] molecules would be required to exactly react with the [tex]\rm NH_3\![/tex] in the original solution and hence reach the equivalence point of this titration.
Calculate the volume of that [tex]0.3733\; \rm mol \cdot L^{-1}[/tex] [tex]\rm HCl[/tex] solution required for reaching the equivalence point of this titration:
[tex]\begin{aligned}V({\rm HCl}) &= \frac{n({\rm HCl})}{c({\rm HCl})} \\ &\approx \frac{0.154375\; \rm mol}{0.3733\; \rm mol \cdot L^{-1}} \approx 0.413541\; \rm L\end{aligned}[/tex].
Hence, by the assumption stated in the question, the volume of the solution at the equivalence point would be approximately [tex]0.413541\; \rm L + 0.1900\; \rm L \approx 0.6035\; \rm L[/tex].
If no hydrolysis took place, [tex]0.154375\; \rm mol[/tex] of [tex]\rm NH_4 Cl[/tex] would be produced. Because [tex]\rm NH_4 Cl\![/tex] is a soluble salt, the solution would contain [tex]0.154375\; \rm mol\![/tex] of [tex]\rm {NH_4}^{+}[/tex] ions. The concentration of [tex]\rm {NH_4}^{+}\![/tex] would be approximately:
[tex]\begin{aligned}c({\rm {NH_4}^{+}}) &= \frac{n({\rm {NH_4}^{+}})}{V({\rm {NH_4}^{+}})}\\ &\approx \frac{0.154375\; \rm mol}{0.6035\; \rm L} \approx 0.255782\; \rm mol \cdot L^{-1}\end{aligned}[/tex].
However, because [tex]\rm NH_3 \cdot H_2O[/tex] is a weak base, its conjugate [tex]\rm {NH_4}^{+}[/tex] would be a weak base.
[tex]\begin{aligned}pK_{\rm a}({{\rm NH_4}}^{+}) &= pK_{\rm w} - pK_{\rm b}({\rm NH_3})\\ &\approx 13.99 - 4.75 = 9.25\end{aligned}[/tex].
Hence, the following reversible reaction would be take place in the solution at the equivalence point:
[tex]\rm {NH_4}^{+} \rightleftharpoons NH_3 + H^{+}[/tex].
Let [tex]x\; \rm mol \cdot L^{-1}[/tex] be the increase in the concentration of [tex]\rm H^{+}[/tex] in this solution because of this reversible reaction. (Notice that [tex]x \ge 0[/tex].) Construct the following [tex]\text{RICE}[/tex] table:
[tex]\begin{array}{c|ccccc} \textbf{R}& \rm {\rm NH_4}^{+} & \rightleftharpoons & {\rm NH_3}& + & {\rm H}^{+}\\ \textbf{I} & 0.255782 \; \rm M \\ \textbf{C} & -x \;\rm M & & + x\;\rm M & & + x\; \rm M \\ \textbf{E} & (0.255782 - x)\; \rm M & & x\; \rm M & & x\; \rm M\end{array}[/tex].
Thus, at equilibrium:
Concentration of the weak acid: [tex][{\rm {NH_4}^{+}}] \approx (0.255782 - x) \; \rm M[/tex].Concentration of the conjugate of the weak acid: [tex][{\rm NH_3}] = x\; \rm M[/tex].Concentration of [tex]\rm H^{+}[/tex]: [tex][{\rm {H}^{+}}] \approx x\; \rm M[/tex].[tex]\displaystyle \frac{[{\rm NH_3}] \cdot [{\rm H^{+}}]}{[{ \rm {NH_4}^{+}}]} = 10^{pK_\text{a}({\rm {NH_4}^{+}})}[/tex].
[tex]\displaystyle \frac{x^2}{0.255782 - x} \approx 10^{-9.25}[/tex]
Solve for [tex]x[/tex]. (Notice that the value of [tex]x\![/tex] is likely to be much smaller than [tex]0.255782[/tex]. Hence, the denominator on the left-hand side [tex](0.255782 - x) \approx 0.255782[/tex].)
[tex]x \approx 1.19929 \times 10^{-5}[/tex].
Hence, the concentration of [tex]\rm H^{+}[/tex] at the equivalence point of this titration would be approximately [tex]1.19929 \times 10^{-5}\; \rm M[/tex].
Hence, the [tex]pH[/tex] at the equivalence point of this titration would be:
[tex]\begin{aligned}pH &= -\log_{10}[{\rm {H}^{+}}] \\ &\approx -\log_{10} \left(1.19929 \times 10^{-5}\right) \approx 4.92\end{aligned}[/tex].
what’s the answer please
Answer:
5 × 10⁻³ mol
Explanation:
Step 1: Given data
Volume of HCl solution (V): 25 cm³Molar concetration of the HCl solution (C): 0.2 mol/dm³Step 2: Convert "V" to dm³
We will use the conversion factor 1 dm³ = 1000 cm³.
25 cm³ × 1 dm³/1000 cm³ = 0.025 dm³
Step 3: Calculate the moles of HCl (n)
We will use the definition of molarity.
C = n/V
n = C × V
n = 0.2 mol/dm³ × 0.025 dm³ = 5 × 10⁻³ mol