A HgO → Hg + O2
B 2Fe + O2 → Fe2O3
Which best represents a
balanced equation?
C 2H2 + O2 → 2H20
An 18.7 g sample of platinum metal increases in temperature from 21.2C to 23.5C
when 5.7 J of heat are added. What is the specific heat of platinum?
Answer:
132.53 J/kg.°C
Explanation:
Applying,
Q = cm(t₂-t₁)................ Equation 1
Where Q = amount of heat, c = specific heat capacity of platinum metal, m = mass of platinum metal, t₁ = initial temperature, t₂ = Final temperature.
Make c the subeject of the equation
c = Q/m(t₂-t₁).............. Equation 2
From the question,
Given: Q = 5.7 J. m = 18.7 g = 0.0187 kg, t₁ = 21.2°C, t₂ = 23.5°C
Substitute these values into equation 2
c = 5.7/[0.0187×(23.5-21.2)]
c = 5.7/0.04301
c = 132.53 J/kg.°C
Which physical change is endothermic?
A.
CO2(g) → CO2(ℓ)
B.
CO2(g) → CO2(s)
C.
CO2(ℓ) → CO2(s)
Answer:
The correct answer is A
Explanation:
Endothermic is a reaction of which heat is provided to break down the reacted molecules
What is the number of moles in 10.62 L of H2S gas at STP?
Answer:
0.474 moles
Explanation:
divide 10.62 by 22.4.
what is the use of connective tissue
Answer:
Major functions of connective tissue include: 1) binding and supporting, 2) protecting, 3) insulating, 4) storing reserve fuel, and 5) transporting substances within the body. Connective tissues can have various levels of vascularity.
Explanation:
What were some of the causes of the Amu Darya and Syr Darya rivers being ruined?
urban sewer drainage
tannery dumping
tourism
drying up
agricultural chemicals
Answer:
drying up
agricultural chemicals
Explanation:
10/28 11. If the subscript indicating the quantity of a particular element in an ionic formula would be one, the numerical value is omitted instead TRUE FALSE Check it skip GET A HINT 2 SCRATCHPAD Improve this question
It is true that if the subscript indicating the quantity of a particular element in an ionic formula would be one, the numerical value is omitted instead.
What is ionic formula?An ionic formula, also known as an ionic compound or salt, is a chemical compound that is composed of positively charged ions (called cations) and negatively charged ions (called anions) held together by ionic bonds. Ionic compounds typically form between a metal and a nonmetal, or between a metal and a polyatomic ion. The ionic formula is a representation of the chemical formula of an ionic compound. It shows the types and numbers of ions that are present in the compound. The cation is written first, followed by the anion, and the subscript for each ion is written to balance the charges. The total charge of the cations and anions must balance to zero in the ionic formula.
Here,
If the subscript indicating the quantity of a particular element in an ionic formula would be one, the numerical value is typically omitted, and the formula is written using only the symbols of the elements. This is because the presence of the element is implied by its symbol, and a subscript of 1 is unnecessary. However, when there is more than one atom of a particular element in the formula, the numerical subscript is required to indicate how many atoms are present.
To know more about ionic formula,
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What is a galvanic cell made of
Answer: A galvanic cell consists of two different metals (electrodes) connected through a conducting solution (an electrolyte) and also connected externally completing a circuit.
How many moles of air are there in a 125 mL Erlenmeyer flask if the pressure is 755
mm Hg and the temperature is 20.0°C?
To Find :
How many moles of air are there in a 125 mL Erlenmeyer flask if the pressure is 755 mm Hg and the temperature is 20.0°C .
Solution :
Since, air contains different gas in different proportion.
Its average molar mass is considered to be 29 gram/mol .
Now, we know by ideal gas equation :
[tex]PV = nRT\\\\n = \dfrac{PV}{RT}[/tex]
Here, R is ideal gas equation, [tex]R = 62.363\ mm\ Hg\ L \ mol^{-1} \ K^{-1}[/tex]
Putting all given values we get :
[tex]n = \dfrac{755 \times 0.125}{62.363\times (20+273)}\ moles\\\\n = 0.00516 \ moles[/tex]
Hence, this is the required solution.
A series of logical steps that is followed in order to solve a problem is called the *
1 point
A. experimental process.
B. scientific theory.
D. scientific method
D. model method
Answer:
YUNG PANGATLO LETER D.
Explanation:
YUN ANG SAGUT :>
Answer:
C. Scientific method
Explanation:
we did this in my middle school and this was the only method we were allowed to use to solve problems or questions we had.
Answer is B
A metal conducts heat in a similar way to electricity so, as you touch it, it draws heat from your body and makes your hand feel cold.
Plastics don't have to conduct heat so they don't draw heat from your body as efficiently, that's why a piece of plastic feels
than a piece of metal even if it's at the same temperature.
A)
long-chain molecules; warmer
B)
free electrons, warmer
valence electrons; colder
D)
a crystalline lattice; colder
When the head of a match burns, chemical reaction is taking place. But a certain amount of energy is required to get this reaction started. This is the reactions activation energy. Describe where this energy comes from. What provides this energy?
Answer:
Rubbing the match against a rough surface
The activation energy is provided by friction between surfaces
Explanation:
Activation energy is the energy required to start a chemical reaction. It is the minimum energy that must be supplied for a reaction to proceed.
When we strike a match against a rough surface, what we are trying to do is to supply the required activation energy in the form of friction in order to get the combustion reaction started.
Hence, the activation energy for the combustion of a match head is supplied by friction when the match head is struck against a rough surface.
11A) As electrical energy is converted into heat energy, the total amount of energy in the system
pls help me out !
Answer:
b. option Is the correct answer
what part of the electromagnetic spectrum was first developed during ww2
Answer:
Radio waves were first developed in WWII
Explanation:
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A solvent has a freezing point of 10°C. What is the most likely freezing point if 5 grams of Salt is mixed with the solvent? (AKS 5e)
Question 5 options:
15°C
20°C
5°C
10°C
[tex]\huge{\color{hotpink}{Hola}}[/tex]
A hydrogen molecule is:
a Polar
b Covalent
C Non-polar
d Both B and C
Explanation:
both b and c since it can be both
26 grams of 2,2 dimethyl hexane( C8H16) under goes combustion. How
much space would the CO2 gas occupy at 26 Celsius and 101.75 kPa?
Answer: The [tex]CO_{2}[/tex] gas occupies a space of 5.57 L at 26 Celsius and 101.75 kPa.
Explanation:
Given: Mass = 26 g
Pressure = 101.75 kPa
Convert kPa into atm as follows.
[tex]1 kPa = 0.00986923 atm\\101.75 kPa = 101.75 kPa \times \frac{0.00986923 atm}{1 kPa}\\= 1 atm[/tex]
Temperature = [tex]26^{o}C = (26 + 273) K = 299 K[/tex]
Now, moles of a substance is defined as mass of substance divided by its molar mass.
As molar mass of 2,2 dimethyl hexane is 114.23 g/mol. So, its number of moles are calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{26}{114.23 g/mol}\\= 0.227 mol[/tex]
Formula used to calculate the volume is as follows.
PV = nRT
where,
P = pressure
V = volume
n = no. of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
[tex]PV = nRT\\1 atm \times V = 0.227 mol \times 0.0821 L atm/mol K \times 299 K\\V = 5.57 L[/tex]
Thus, we can conclude that the [tex]CO_{2}[/tex] gas occupies a space of 5.57 L at 26 Celsius and 101.75 kPa.
Oxygen has a very low boiling point and is a gas at room temperature. Water has a much higher boiling point and is a liquid at room
temperature. Which of these statements would support these facts?
A)
Oxygen is an element while water is a compound.
B)
Oxygen is diatomic and exist as O2 in nature.
Water has a higher attraction between its molecules than oxygen.
D)
Water is a molecule with 3 atoms and oxygen exists in groups of 2.
Answer is C
Which pair of elements will form an ionic bond?
a. Potassium and Oxygen
b. Iron and Barium
C. Sulfur and Nitrogen
d. Calcium and Silicon
I believe that the answer is A.
The combination of potassium (K) and oxygen (O2) produces K2O (potassium oxide). The balanced equation is 2K + O2 ==> K2O.
Which energy source is considered nonrenewable?
1) moving water
2) fossil fuel
3) wind
4) biomass
Answer:
Fossil fuel
Explanation:
Answer:
2
Explanation:
Nonrenewable energy resources include coal, natural gas, oil, and nuclear energy. Once these resources are used up, they cannot be replaced, which is a major problem for humanity as we are currently dependent on them to supply most of our energy needs.
Given the equation below, determine the number of moles O2 required to completely react with 28 moles of CO.
Answer:
14 moles of O₂
Explanation:
The reaction between CO and O₂ is the following:
CO + O₂ → CO₂
We balance the equation with a coefficient 2 in CO and CO₂ to obtain the same number of O atoms:
2CO + O₂ → 2CO₂
As we can see from the balanced equation, 1 mol of O₂ is required to react with 2 moles of CO. Thus, the conversion factor is 1 mol of O₂/2 mol CO. We multiply the moles of CO by the conversion factor to calculate the moles of O₂ that are required:
28 mol CO x 1 mol of O₂/2 mol CO = 14 mol O₂
At a particular temperature, K = 2.0 × 10-6 for the reaction
2CO2(g) ⇌ 2CO(g) + O2(g)
In an experiment 15.95 mol of CO2 is initially placed in a 1.6 L vessel. Calculate the equilibrium concentration of O2.
Give your answer to 4 decimal places.
Answer:
y = 0.037 M = [O₂]
Explanation:
Let's write the equilibrium reaction:
2CO₂ <--------> 2CO + O₂ K = 2x10⁻⁶
The problem states that we have initially 15.95 mol of CO₂ in a 1.6 L vessel. With this we can determine the concentration:
M = moles / V
[CO₂] = 15.95 / 1.6 = 9.97 M
Now, we need to write an ICE chart so we can have the equilibrium concentrations:
2CO₂ <--------> 2CO + O₂ K = 2x10⁻⁶
I. 9.97 0 0
C. -2y +2y +y
E. 9.97-2y 2y y
K = [CO]² [O₂] / [CO₂]² Replacing we have:
2x10⁻⁶ = (2y)² (y)² / (9.97 - 2y)² But K is <10⁻⁴ so we can neglect the substraction of 9.97 - 2y, we have then:
2x10⁻⁶ = 4y² (y) / (9.97)²
2x10⁻⁶ * (9,97)² = 4y³
y = ∛2x10⁻⁶ * (9,97)² / 4
y = 0.037 M = [O₂]Hope this helps
WILL GIVE BRAINLIEST!
__ gain electrons in the formation of ionic bonds because they have such high ionization energies indicating a strong attraction between the electrons and the nucleus.
A- metals
B- nonmetals
Answer:
A-Metals
Explanation:
because they have valence electrons
name 3 common acids that you use in your home
Answer:
vinegar, soft drinks, seltzer water , citrus fruits
Explanation:
NEED ANSWER FAST !!
Using the following equation,
a. Balance the equation by putting the smallest whole number coefficient in each blank
Fe2O3 + H2 à Fe + H2O
b. Use the balanced equation to calculate how many grams of iron can be made from 0.025 mol of Fe2O3
Answer: grams Fe (Round your answer to the nearest hundreths)
Answer:
.-.
Explanation:
How can one determine that a redox reaction will be nonspontaneous?
Answer:
A redox reaction is spontaneous if the standard electrode potential for the redox reaction, Eo(redox reaction), is positive. ...
If Eo(redox reaction) is positive, the reaction will proceed in the forward direction (spontaneous)
Explanation:
thank me later
Answer:
C. The reduction potential plus oxidation potential is negative.
Explanation:
it was right lol
When propane burns, heat and light are produced. Where does this energy come from?
Answer:
It releases energy from the breaking of bonds during its combulsion stages.
Explanation:
(This expanation is not from me, its from qizzlet.com. but the anserw is made by me)
When propane burns, heat and light are produced. Where does this energy come from? The energy comes from, the breaking of the bonds and it is being released.
have a great day17 moles of oxygen is equals to how many grams
17 × ( 2 × 16 ) = 17 × 32 = 544 grams
___________________________
When a substance changes from a gas to a liquid, what happens to the energy, order, and spacing of
particles within the substance?
I
Answer:
Explanation:
When gas changes to liquid, it releases the thermal energy that has been absorbed before to become gas which does not alter the temperature at all. A reduction in energy changes the arrangement of particle. There spacing between the particles also increases but not as in a gaseous state and so does the kinetic energy. The particles now are now arranged in irregular pattern.
Select the correct answer. Which statement is true for a heating curve?
OA. It shows how the pressure of a substance changes when heated.
ов. It shows how the temperature of a substance changes when heated
OC. It shows how the volume of a substance changes when heated.
OD. It shows how the mass of a substance changes when heated.
please help
Answer:
OB
Explanation:
tht is correct make me brainliest