Answer:
b) From the person to the ice, and from the air to the ice
Explanation:
The direction of heat flow in the room is from the person to the ice and from the air to the ice.
The ice is at the lowest temperature.
Heat flows from a place with a higher measure of heat to a place with a lower amount of heat. Since the ice has the lowest heat, there is a thermal gradient set up. Heat will flow from the body and air towards to the ice.When 50.0 mL of 0.400 M Ca(NO3)2 is added to 50.0 mL of 0.800 M NaF, CaF2 precipitates, as shown in the netionic equation below. The initial temperature of both solutions is 23.0°C. Assuming that the reaction goes tocompletion, and that the resulting solution has a mass of 100.00 g and a specific heat of 4.18 J/(g ∙°C), calculatethe final temperature of the solution.Ca2+(aq) + 2 F-(aq) → CaF2(s)∆H°=-11.5 kJ
Answer:
23.55°C
Explanation:
Based on the equation:
Ca²⁺(aq) + 2F⁻(aq) → CaF₂(s) ∆H°=-11.5 kJ
When 1 mole of Ca²⁺ and 2 of F⁻ reacts, 11.5kJ are released.
Thus, we need to find moles of reaction to find the heat released and using:
C = SₓmₓΔT
We can find the final temperature as follows:
Moles of reaction:
0.0500L * (0.400mol / L) = 0.0200moles Ca²⁺ = Moles of reaction
Heat produced is:
0.0200 moles * (11.5kJ / mol) = 0.23kJ
Using:
C = SₓmₓΔT
Where C is heat = 230J
S is specific heat = 4.18J/g
m is mass of solution = 100.00g
And ΔT is change in temperature
230J = 4.18J/gₓ100.00gₓΔT
ΔT = 0.55°C
As initial temperature is 23.0°C
Final temperature = 23.0°C + 0.55°C =
23.55°CThe final temperature of the solution is 23.55°C.
We were given the equation
Ca²⁺(aq) + 2F⁻(aq) → CaF₂(s) ∆H°=-11.5 kJ
This means that 1 mole of Ca²⁺ and 2 of F⁻ reacts to form CaF₂ and 1.5kJ is released.
The formula we need to use is C = SₓmₓΔT
where c is heat, s is specific heat, m is number of mole and ΔT is temperature change.
We need to find the moles of reaction first
Moles of reaction = 0.0500L × (0.400mol / L) = 0.0200moles Ca²⁺
Heat produced = 0.0200 moles ×11.5kJ / mol = 0.23kJ
We can then substitute into the formula
C = SₓmₓΔT
C = 230J
S = 4.18J/g
m = 100.00g
ΔT= ?
230J = 4.18J/gₓ100.00gₓΔT
= 0.55°C
Since the initial temperature is 23.0°C
The Final temperature will be 23.0°C + 0.55°C
=23.55°C
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12oz of water initially at 75oF is mixed with 20oz of water intiially at 140oF. What is the final temperature?
Answer:
[tex]115.625^{\circ}\text{F}[/tex]
Explanation:
[tex]m_1[/tex] = First mass of water = 12 oz
[tex]m_2[/tex] = Second mass of water = 20 oz
[tex]\Delta T_1[/tex] = Temperature difference of the solution with respect to the first mass of water = [tex](T-75)^{\circ}\text{F}[/tex]
[tex]\Delta T_2[/tex] = Temperature difference of the solution with respect to the second mass of water = [tex](T-75)^{\circ}\text{F}[/tex]
c = Specific heat of water
As heat gain and loss in the system is equal we have
[tex]m_1c\Delta T_1=m_2c\Delta T_2\\\Rightarrow m_1\Delta T_1=m_2\Delta T_2\\\Rightarrow 12(T-75)=20(140-T)\\\Rightarrow 12T-900=2800-20T\\\Rightarrow 12T+20T=2800+900\\\Rightarrow 32T=3700\\\Rightarrow T=\dfrac{3700}{32}\\\Rightarrow T=115.625^{\circ}\text{F}[/tex]
The final temperature of the solution is [tex]115.625^{\circ}\text{F}[/tex].
A 45.0 mL solution of 0.0450 M hydroxylamine is extracted with 125 mL of solvent. The distribution constant for the reaction is 5.00 and the pKa of the protonated form of hydroxylamine is 5.960. Calculate the concentration of hydroxylamine remaining in the aqueous phase at pH=4.50 and pH=6.50 .
Answer:
pH = 4.5, concentration = 0.045 M.
pH = 6.5, concentration = 0.175 M.
Explanation:
The ka for the can be calculated by using the formula below;
Ka = 10^-pka = 10^-5.960 = 1.1 × 10^-6
The concentration of hydrogen ion at pH = 4.50 can be calculated as given below;
{H^+ } = 10^-4.50 = 3.2 × 10^-5 M.
(NB=> 10 in this regards means the inverse of log).
The next step is to determine the distribution coefficient which can be calculated by using the formula below;
distribution coefficient = (partition coefficient) × ka / ka + ( concentration of Hydrogen ion,H^+).
distribution coefficient =( 5 × 1.1 × 10^-6 ) / 1.1 × 10^-6 + 3.2 × 10^-5 M. = 5.5 × 10^-6/ 3.2 = 0.00000171875
The fraction remaining from the compound = 45.0 mL / 45.0 mL + (0.00000171875 × 125).
= 0.999995.
Thus, the concentration at pH = 4.5 = 0.999995 × 0.0450 M = 0.045 M
(B). pH=6.50, thus the concentration of Hydrogen ion = 10^-6.5 = 3.2 × 10^-7 M.
distribution coefficient = (partition coefficient) × ka / ka + ( concentration of Hydrogen ion,H^+).
distribution coefficient = (5 × 1.1 × 10^-6)/ 1.1 × 10^-6 + 3.2 × 10^-7 M).
distribution coefficient = 5.5 × 10^-6/ 1.42 × 10^-6 = 3.9.
Therefore, the concentration = 3.9 × 0.0450 M = 0.175 M.
What evidence would a scientist use to determine the age of rock in a layer?
Answer: They can find fossils and use a technology called radiocarbon to find the age of the fossil and then do an approximate about the age of the rock.
Explanation:
Fluorine gas and water vapor react to form hydrogen fluoride gas and oxygen. What volume of oxygen would be produced by this reaction if 2.6em of were consumed? Also, be sure your answer has a unit symbol, and is rounded to the correct number of significant digits
Answer:
The reaction is 2F_2 (g) + 2H_2 O (g) rightarrow 4HF (g) + O_2 (g) 2 moles of fluorine gas (F_2) reacts with 2 moles of water vapors (H_2 O) to produce 4 moles of hy
How many milliliters of 6.2 M M HCl H C l solution are needed to obtain 0.18 mol m o l of HCl H C l ?
Answer:
29 mL HCl
General Formulas and Concepts:
Chem
Molarity = moles of solute / liters of solutionExplanation:
Step 1: Define
6.2 M HCl
0.18 mol HCl
x L mol HCl
Step 2: Define conversions
1 L = 1000 mL
Step 3: Find L
6.2 M HCl = 0.18 mol HCl / x L HCl
(x L HCl)(6.2 M HCl) = 0.18 mol HCl
x L HCl = 0.18 mol HCl / 6.2 M HCl
x = 0.029032 L HCl
Step 4: Convert
[tex]0.029032 \ L \ HCl(\frac{1000 \ mL \ HCl}{1 \ L \ HCl} )[/tex] = 29.0323 mL HCl
Step 5: Check
We are given 2 sig figs. Follow sig fig rules.
29.0323 mL HCl ≈ 29 mL HCl
Answer:
29 mL HCl
Explanation:
Which of the following set of properties is most likely for a liquid with large, attractive intermolecular forces?
Answer:
is it ok na I hope this answers are ok
Answer:
Answer is: C) high melting point and high boiling point.
Explanation:
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write the chemical formula of tetraphosporus osctasulfide
Answer:
P4S8 .
the chemical formula of Tetraphosporus osctasulfide is p4S8
1+1 hahahahahhhahahaahahahahahahahahahahahahahaha why u dumb
Answer:
1+1=2 Unless this is a trick question. Then it's most likely 11.
Explanation:
1 + 1 = 2
thxs for the points realy tho thxs
Heavier compounds tend to have higher boiling points. However, sulphur dichloride (Mr= 103.1 gmol-1) and sulphur hexafluoride (Mr = 146.1 g mol-1) have the boiling point of 59 °C and -50.8 °C respectively. Explain this phenomenon.
Consider the following reaction:2 HgCl2(aq) + C2O42-(aq) 2 Cl-(aq) + 2 CO2(g) + Hg2Cl2(s)(a) The rate law for this reaction is first order in HgCl2(aq) and second order in C2O42-(aq). What is the rate law for this reaction?Rate = k [HgCl2(aq)] [C2O42-(aq)]Rate = k [HgCl2(aq)]2 [C2O42-(aq)]Rate = k [HgCl2(aq)] [C2O42-(aq)]2Rate = k [HgCl2(aq)]2 [C2O42-(aq)]2Rate = k [HgCl2(aq)] [C2O42-(aq)]3Rate = k [HgCl2(aq)]4 [C2O42-(aq)](b) If the rate constant for this reaction at a certain temperature is 0.0169, what is the reaction rate when [HgCl2(aq)] = 0.158 M and [C2O42-(aq)] = 0.202 M?Rate = M/s.(c) What is the reaction rate when the concentration of HgCl2(aq) is doubled, to 0.316 M while the concentration of C2O42-(aq) is 0.202 M?Rate = M/s
Answer:
b
Explanation:
The compound F20 has two lone pairs on the central oxygen atom. What's the structure of an F2O molecule? Is this compound polar or non-polar?
A. Trigonal planar, polar
B. Bent or angular non-polar
C. Bent or angular polar
D. Trigonal planar non-polar
Answer:
Bent or Angular, Polar
Explanation:
I just took the test!
Answer:
C. Bent or angular polar
Explanation:
The density of krypton gas at 1.35 atm and 54.1°C is ________ g/L.
a. 4.21
b. 0.304
c. 8.42
d. 0.0503
e. 0.237
a.
Explanation: I saw it on another website.
After an afternoon party, a small cooler full of ice is dumped onto the hot ground and melts. If the cooler contained 6.60 kg of ice and the temperature of the ground was 42.5 °C, calculate the energy that is required to melt all the ice at 0 °C. The heat of fusion for water is 80.0 cal/g.
Answer:
The quantity of heat required to melt all the ice at 0°C is 2.21 * 10⁶ J
Explanation:
Latent heat of fusion is the heat absorbed by a unit mass of a given solid at its melting point that completely converts the solid to a liquid at the same temperature. Its unit is Joules/kg or Joules/g.
1 calorie = 4.184 Joules
Therefore , 80.0 cal/g = 80.0 cal/g * 4.184 J/cal = 334.72 J/g
1 g = 0.001 kg; Heat of fusion in J/kg = 334.72 J/g * 1g /0.001 kg = 3.35 * 10⁵ J/kg
Quantity of heat, Q = mass * latent heat of fusion of ice
quantity of heat required = 6.60 kg * 3.35 * 10⁵ J/kg
Quantity of heat required = 2.21 * 10⁶ J
Therefore, the quantity of heat required to melt all the ice at 0°C is 2.21 * 10⁶ J
The nucleus of an atom is made up of which of the following combinations of particles?
Answer: Atoms of different elements are found to have different number of protons, neutrons, and electrons. To distinguish one atom from another or to classify the various atoms, a number which indicates the number of protons in the nucleus of a given atom, is assigned to the atoms of each identified element. This number is known as the atomic number of the element. The atomic numbers for some of the elements which are associated with the study of semiconductors are given in the following table.
Explanation:
Element Symbol Atomic Number
Silicon Si 14
Germanium Ge 32
Arsenic As 33
Antimony Sb 51
Indium In 49
Gallium Ga 31
Boron B 5
Answer:
[tex]\boxed {\boxed {\sf Protons \ and \ neutrons}}[/tex]
Explanation:
The atom is made up of two main parts: the nucleus and the electron cloud.
The nucleus is the center and has two subatomic particles: the protons (positive charge) and the neutrons (no/neutral charge). The nucleus as a whole has a positive charge, since the neutrons don't provide a charge.
The electron cloud surrounds the nucleus and houses the negatively charged electrons in a "cloud" of energy levels.
So, the nucleus of the atom is made up of protons and neutrons.
Balance the following chemical equations:
N2+02___N2O
Answer:
Balance the following chemical equations:
Explanation:
2N2 + O2 → 2N2O
the position-time graph shows the motion of four people. label the lines on graph need on the motion description in this table.
Answer:
4,2,3,1
Explanation:
determine moles of 1.5g of sodium carbonate.
Answer:
0.014mol
Explanation:
Given parameters:
Mass of Na₂CO₃ = 1.5g
Unknown:
Number of moles = ?
Solution:
Number of moles of a compound is mathematically expressed as;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of Na₂CO₃ = 2(23) + 12 + 3(16) = 106g/mol
Number of moles = [tex]\frac{1.5}{106}[/tex] = 0.014mol
will give branliest
How many grams of liquid water are produced when 60 grams of ice melt? Explain why.
60 Grams are produced due to the fact that it may not produce more due to the certain capacity that varies on the size of the cube.
A mixture of 10.0 g of Ne and 10.0 g Ar have a total pressure of 1.60 atm. What is the partial pressure of Ar
Answer:
0.53 atm
Explanation:
First we have to obtain the number of moles of each gas.
Number of moles of Ne = 10g/20g/mol = 0.5 moles
Number of moles of Ar = 10 g/40 g/mol = 0.25 moles
Total number of moles = 0.5 moles + 0.25 moles = 0.75 moles
Partial pressure of Ar = number of moles of Ar/Total number of moles * total pressure
Partial pressure of Ar = 0.25 moles/ 0.75 moles * 1.60 atm
Partial pressure of Ar = 0.53 atm
Sunday
Monday
What
The
Freak
Saturday
A scientist wants to make a solution of tribasic sodium phosphate, Na3PO4, for a laboratory experiment. How many grams of Na3PO4 will be needed to produce 725 mL of a solution that has a concentration of Na ions of 1.30 M
Answer:
51.53 grams .
Explanation:
Na₃PO₄ ⇄ 3Na⁺¹ + PO₄⁻³ .
1 mole 3 mole
725 mL of 1.3 M Na⁺ ions
= .725 x 1.3 moles of Na⁺ ions
= .9425 moles
3 mole of Na⁺ is formed by 1 mole of Na₃PO₄
.9425 mole of Na⁺ is formed by .9425/3 mole of Na₃PO₄
Na₃PO₄ needed = .9425/3 moles = .3142 moles
Molecular weight of Na₃PO₄ = 164
grams of Na₃PO₄ needed = .3142 x 164 = 51.53 grams .
A. 1
B. 2
C. 3
D. 4
_______________________________________________________
Which is the best example and explanation that a physical change has occurred?
fireworks exploding, because energy is released as light and heat
gasoline burning, because it forms water vapor and carbon dioxide
O crushing an ice cube, because the chemical structure of the ice cube is changed
dicing potatoes, because the molecules are separated but remain the same substance
dicing potatoes, because the molecules are separated but remain the same substance
Answer:
For the people wondering, yes, dicing potatoes is the correct answer. Because a new substance has not formed.
Calculate the final temperature (once the ice has melted) of a mixture made up initially of 70.0 mL liquid water at 28 oC and 5.0 g ice at 0.0 oC.
Answer:
21.52° C
Explanation:
From the given information:
mass of the liquid water = 70.0 mL
Initial temperature = 20°C
mass of the ice = 5.0 g
temperature of ice = 0.0°C
Using the calorimetric function:
heat lost by water = heat gained by ice.
mass of water × specific heat of water (s) × ΔT = mass of ice × specific heat of ice (s) × ΔT + n (ΔH_fusion}
⇒ 70 × 4.184 × (28 -x) = 5 × 2.108(x - 0) + [tex](\dfrac{5}{18})[/tex] × 6.01 × 10³
By solving the above equation,
x = 21.52° C
The final temperature of the mixture of water and ice is 21.5 ⁰C.
The given parameters;
initial volume of the liquid = 70 mL initial temperature of the water, = 28⁰Cmass of the ice, = 5.0 gtemperature of the ice, = 0⁰ Cspecific heat capacity of ice = 2.09 J/g ⁰Cheat of fusion of ice = 333.55 J/gspecific heat capacity of water = 4.184 J/g⁰ Cdensity of water = 1 g/mlLet the final temperature of the mixture = t
mass of the liquid water = 1 g/ml x 70 ml = 70 g
Apply the principle of conservation of energy to determine the final temperature of the mixture;
heat lost by water = heat gained by ice
[tex]70 \times 4.184(28 - t) = 5\times 2.09(t - 0) \ + \ 5 \times 333.55\\\\8200.64 - 292.88t = 10.45 t + 1667.75\\\\303.33t = 6532.89\\\\t = \frac{6532.89}{303.33}\\\\t = 21.5 \ ^0C[/tex]
Thus, the final temperature of the mixture of water and ice is 21.5 ⁰C.
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Write a balanced half-reaction for the oxidation of gaseous nitric oxide (NO) to aqueous nitrous acid (HNO2) in acidic aqueous solution.
Answer:
NO + H₂O → HNO₂ + 1 e- + 1 H⁺
Step-by-step explanation:
NO ⇒ oxidation number of N = +2
HNO₂ ⇒ oxidation number of N= +3
Therefore, NO has to lose 1 electron to be oxidized to HNO₂. We write the half-reaction with 1 electron (1 e-) in the products side.
NO → HNO₂ + 1 e-
Now, we have 0 electrical charges in the reactants side, and a total of -1 electrical charge in the products side. As the reaction is in acidic aqueous solution, we have to add H⁺ ions to balance the charges. We perform the balance by adding 1 H⁺ (positive charge) to neutralize the negative charge in the side of the products:
NO → HNO₂ + 1 e- + 1 H⁺
Now, we perform the mass balance. We have:
N: 1 atom in both sides
O: 1 atom in reactants side and 2 atoms in products side
H: 0 atoms in reactants side, 2 atoms in products side.
Thus, we have to add 1 H₂O molecule to the reactants side to equal the masses:
NO + H₂O → HNO₂ + 1 e- + 1 H⁺
Finally, the oxidation half-reaction is:
NO + H₂O → HNO₂ + 1 e- + 1 H⁺
How many seconds are in 100 years(factor label conversion)
Answer:
0.0166
Explanation:
This conversion of 100 seconds to minutes has been calculated by multiplying 100 seconds by 0.0166 and the result is 1.6666 minutes.
I hope this helps,
even a little bit
If the concentration of a reactant is tripled (all other things remain constant), and the reaction rate increases nine times, what is the reaction order with respect to the tripled reactant? Enter your answer as a number.If the concentration of a reactant is increased 1.5 times (all other things remain constant), and the reaction rate increases 2.25 times, what is the reaction order with respect to the reactant? Enter your answer as a number.If the concentration of a reactant is tripled (all other things remain constant), and the reaction rate remains constant, what is the reaction order with respect to the tripled reactant? Enter your answer as a number.When 29.0 mL of 0.220 M KIO3 is combined with 38.0 mL of H2SO3 and 50.0 mL of water, what is the resulting concentration of KIO3?
The reaction order for the following conditions are:
a. two
b. two
What do you mean by reaction order?Reaction order is the number of reactants, whose concentration affects the reaction rate.
The reaction order can be determined by adding the exponents of each reactant.
The rate equation is [tex]v^0 = k[A]^x + k[B]^y[/tex]
The first-order reaction is in which the reaction is dependent on one variable concentration.
The second-order reaction is that in which the reaction is dependent upon the concentration of two variables.
Thus, the correct options are a. two, b.two.
Learn more about reaction order
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What forces cause mechanical weathering? Choose more than one
answer.
Answer:
mineral crystal growth
acid rain
carbonic acid
Answer:
Mineral crystal growth, Acid rain, Carbonic acid
4. One mole of oxygen contains 6.02 x 102 molecules. How many oxygen molecules are in
5.55 moles of oxygen gas?|
Answer:
3.34x10²⁴ molecules of oxygen
Explanation:
1 Mole of particles of any kind of gases or particles are always 6.022x10²³.
1 mole of electrons are 6.022x10²³ electrons
1 mole of any gas are 6.022x10²³ molecules
1 mole of oxygen are 6.022x10²³ molecules. Thus, 5.55 moles are:
3.34x10²⁴ molecules of oxygen