Specific heat capacity of a substance is the amount of heat required to raise the temperature by one degree celsius of one gram of a substance. Therefore, the initial temperature of water is 27.0°C.
What is Enthalpy?
Enthalpy term is basically used in thermodynamics to show the overall energy that a matter have. Mathematically, Enthalpy is directly proportional to specific heat capacity of a substances.
Mathematically,
Enthalpy=mass of solution× specific heat capacity of solution ×Change in temperature.
Enthalpy=1000 J
mass of water=0.05kg
Change in temperature=50-initial
specific heat capacity of solution=4.2
Substituting all the given values we get
1000 J= (0.05kg)(4.2)(50-initial)
initial temperature= 27.0°C
Therefore, the initial temperature of water is 27.0°C.
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Which element has the same number of energy levels as aluminum (Al) and the same number of valence electrons as calcium (Ca)
Answer:
magnesium (Mg)
Explanation:
Answer:
Be (Beryllium)
Explanation:
What is the density of Iodine gas at 2.36 atm and 65.0 °C?
A) 0.026 g/L
B) 0.046 g/L
C) 21.6 g/L
D) 38.3 g/L
Answer:
C
Explanation:
The gas equation can be written as PV = nRT, where
T is in kelvin, so 65 + 273 = 338K
P = 2.36 atm
Mass of Iodine gas = 254 g
R = 0.0821 (gas constant)
So,
P = (2.36*254)/(0.0821*338) = 21.63 g/L
"The density of iodine gas at 2.36 atm and 65.0 °C is 21.63 g/L."
What is density?
A substance's density will be its mass per unit volume. The most common symbol for density is D.
The formula of density can be written as:
D= P×MW/RT
where, P is pressure, MW is molecular weight( MW of iodine is 254) and R is gas constant( 0.082).
Now, put the value of given data in above equation.
D= 2.36×254/0.082×338= 21.63 g/L.
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true or false? no atoms are gained or lost in a chemical reaction
Answer: this is true
The two main postulates that was given by Antoine Lavoisier are, oxygen play an important role in combustion and the other is mass of the reactant and product is conserved. Therefore, the given statement is true.
What is law of conservation of mass?
According to Law of conservation of mass, mass can neither be created nor be destroyed. Mass can only be transformed from one form to another. The law of conservation of mass was given by Antoine Lavoisier. Every reaction in nature follow the law given by Antoine Lavoisier that is mass is always conserved.
According to this law, the number and types of atoms on reactant and product side is same. The statement " no atoms are gained or lost in a chemical reaction" is very much correct.
Therefore, the given statement is true.
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Iron is more reactive than copper. Write an activity to show this. Write word equation of the reaction involved.
Answer:
This can be proved by the following activity: Take some Iron fillings and dip them in the Copper sulphate solution. After some time you will notice that there is a colour change in the solution which is caused due to the displacement of Copper from it solution.
Explanation:
When water is heated a physical change occurs and it forms steam. When a lighted splint is applied to hydrogen gas, a chemical change occurs producing water in the form of steam. Explain how these two statements show two differences between physical and chemical changes.
Answer:
- A new substance was formed in the chemical change while no be substance was formed in the physical change
- The chemical change involved a change in chemical composition while the physical change involved no change in chemical composition
Please find the explanation below.
Explanation:
A physical change is a change that does not alter the chemical content of the substances involved, hence, no new substances are produced while a chemical change alters the chemical composition, hence, new substances results.
In this question,
- Water is heated till it forms steam is characterized as a physical change
- Lighted splint is applied to hydrogen gas to produce water in the form of steam is characterized as a chemical change.
- The first process is a PHYSICAL CHANGE because it involved only a change of state i.e. from liquid to gas, hence, no alteration to the chemical composition of the molecule and also no new substance is produced.
- The second process is a CHEMICAL CHANGE because there was a chemical combination of hydrogen gas and the oxygen in the lighted splint to yield water molecules ( a new substance). Therefore, it involved a chemical reaction and formation of a new substance
Geologists apply various methods to study the layers of the earth. Which if the following is a method used to study the deaths layers
Answer: ???
Explanation:???
⚠️help pls ⚠️
80 kg of element X decays so that 2.5 kilograms remain after 40.35 days.
a.What is the half-life of element X?
b. Identify element x.
C. Write a decay equation for the process.
⚠️WILL GIVE BRAINLIEST⚠️
Answer:
A half life of element is 8.07 days
B iodine 131
C check equation in attached image
Explanation:
80/2 =40
40/2=20
20/2=10
10/2=5
5/2=2.5
After 5 half lives it becomes 2.5 kg
n is the number of half-lives that pass in a given period of time
n= period of time/ half-life
Half life =period of time / n
Half life = 40.35/5= 8.07 days
odine-131 → xenon-131 + beta particle
Which kind of weather usually forms over the northwest United States in the summer because of maritime polar air masses? fog dry heat heavy snow heavy rain
Answer:
fog
Explanation:
Answer:
Fog :)
Explanation:
:) :) :) :) :) :) :) :) :) :) :) :) :)
Which of the following elements can form a covalent (molecular) bond with nitrogen?
A. Oxygen
B. Magnesium
C. Sodium
D. Neon
Oxygen can form a covalent (molecular) bond with nitrogen. Hence, option A is correct.
What is a covalent bond?A covalent bond consists of the mutual sharing of one or more pairs of electrons between two atoms.
Two covalent bonds form between the two oxygen atoms because oxygen requires two shared electrons to fill its outermost shell.
Nitrogen atoms will form three covalent bonds (also called triple covalent) between two atoms of nitrogen because each nitrogen atom needs three electrons to fill its outermost shell.
Hence, option A is correct.
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How much of the electromagnetic spectrum is visible to us
A. all of it
B. None of it
C. Most of it
D. A small part of it
(05 06 MC) The theoretical yields of Cl2 from certain starting amounts of MnO2 and HCl were calculated as 65.36 g and 68.08 g, respectively.
If the percentage yield of Cl2 is 70%, what is its actual yield?
42.25g
45.65g
46.33g
47.66g
Actual yield : 45.752 g ⇒no option
Further explanationGiven
The theoretical yields of Cl₂ : 65.35 g and 68.08 g
Required
The actual yield
Solution
Reaction
4 HCl (aq) + MnO₂ (s) → MnCl₂ (aq) + Cl₂ (g) + 2H₂O (l)
Because there are two theoretical yields, then we can choose the smallest one because the value is usually determined from the limiting reactant (in this reaction the limiting reactant is MnO₂)
So 65.36 g is The theoretical yields of Cl₂
Then the actual yield :
[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\actual=\%yield\times theoretical\\\\actual=70\%\times 65.36=45.752[/tex]
1. What type of element (metal, nonmetal, metalloid) is present that accounts for the flame coloration?
Answer:
Metals i guess
Explanation:
Because each element has an exactly defined line emission spectrum, scientists are able to identify them by the color of flame they produce. For example, copper produces a blue flame, lithium and strontium a red flame, calcium an orange flame, sodium a yellow flame, and barium a green flame.
Francium must lose one electron to get a full outer shell. What is the name of the group to which francium belongs
Answer:
Francium (Fr), heaviest chemical element of Group 1 (Ia) in the periodic table, the alkali metal group. It exists only in short-lived radioactive forms.
There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Francium belongs to alkali metals group.
What is periodic table?Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.
Francium is a radioactive element, the electronic configuration of Francium is [ R n] 7s¹. The number of electron in outermost shell s is 1. This shows that francium belongs to group 1 of periodic table that is alkali metals.
Therefore, Francium belongs to alkali metals group.
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Which of the following statements
is/are true about the region of the
atom labeled "x" in the attached
picture?
Explanation:
The region x of the atom shown is called the nucleus of the atom shown. The nucleus of an atom contains protons and neutrons.
Protons are the positively charged particles found in the nucleusNeutrons do not carry any charges. Together protons and neutrons determines the mass of the atom. The mass of an atom is concentrated in the nucleusBoth particles have equal massesThe region y is the atomic orbital where electrons can be found.
Why are we measuring the bubbles to determine the rate of photosynthesis?
Photosynthesis produces glucose and molecular oxygen. The bubbles formed here, is oxygen gas and which can be measured to determine the rate of photosynthesis.
What is photosynthesis?Photosynthesis is a biochemical process by which plants produce energy and oxygen gas with the aid of light. Chlorophyll in green leaves are the photoactive substance which absorbs light energy.
The overall reaction of photosynthesis is written as below:
[tex]\rm 6H_{2}O (l) +6CO_{2} (g) \rightarrow C_{6}H_{6}O_{12}(aq) +6 O_{2} (g)[/tex]
Here, six moles of water and 6 moles of carbon dioxide reacts together to form glucose and 6 moles of oxygen.
The rate of a reaction can be determined by analyzing the product formed at regular interval. Therefore, by measuring the oxygen gas released from photosynthetic reaction in the form of bubbles the rate of reaction can be studied.
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OMG GUESS WHAT GUYS YAYAYA
Answer:
What What What
Explanation:
Answer:
HAPPY BIRTHDAY!
Explanation:
Describe how you mathematically convert the measured mass of a
substance to moles? Create an example. PLEASE HELP
Answer:
no. of moles = measured mass of substance/ molar mass of the constituted elements
Explanation:
No. of moles of 2.0g NaCl= 2/(23+35.5) = 0.034mol
What object can an S wave travel through?
-air
-magma
-soil
-water
Answer:
Magma
Explanation: cuz S waves travel through solids water, soil, and air are not solids so ur answer is B; magma
Answer:
c. soil
Explanation:
this is the correct answer not the one above...
As the radius of a star increases, how do you think its luminosity might change?
Answer:
As the size of a star increases, luminosity increases. If you think about it, a larger star has more surface area. That increased surface area allows more light and energy to be given off.
What is an example of heating water until it boils?
12. Which of these elements is most likely to attract electrons from another atom during chemical bonding?
O 1) Fe
2) C
3) AI
4) Cs
I think the correct answer of these qusion is 2
Is dihydrogen monoxide a real substance? Do you think it should be banned?
Giselle is working with a chemical substance in a laboratory. She observes that when the chemical is heated, it gives off a gas. She assumes that the gas is oxygen but decides to test this assumption to verify it. Which type of scientific knowledge is Giselle’s assumption?
The question is incomplete, the complete question is;
Giselle is working with a chemical substance in a laboratory. She observes that when the chemical is heated, it gives off a gas. She assumes that the gas is oxygen but decides to test this assumption to verify it. Which type of scientific knowledge is Giselle’s assumption?
A.
fact
B.
hypothesis
C.
law
D.
observation
E.
theory
Answer:
B.
hypothesis
Explanation:
A hypothesis is an intelligent guess put forward to explain an experimental observation. It is a tentative explanation for a scientific observation which must be subjected to careful verification.
Giselle’s assumption that the gas evolved is oxygen is a hypothesis. It must now be tested carefully in order to verify if the hypothesis is true.
What is the electron configuration of chlorine (CI)?
O 1s?2s?2p°3s?3p³
O 1s2s?2p3s?3p5
O 1s2s22p3s?4s?3p3
O 1s?2s?2p3s?3p²3d
Hello! :)
[tex]\large\boxed{1s^{2}2s^{2}2p^{6}3s^{2}3p^{5}}[/tex]
Chlorine is a halogen located in group 7A and period 3 of the periodic table.
We can write the electron configuration of this element. Since it is in period 3, the highest configuration level will be at 3.
Chlorine is also located in the p block (nonmetal) section of the table, so the final part of the written configuration will involve "3p".
Recall that:
S block: up to 2 electrons
P block: up to 6 electrons
Chlorine has 17 electrons
Fill in the order of s block to p block. The first level only goes up to an s block. The configuration should sum up to 17 total electrons in total.
We can write the configuration as:
[tex]1s^{2}2s^{2}2p^{6}3s^{2}3p^{5}[/tex]
How many grams are in 1.76 x 10^23 atoms of iodine
Answer:
[tex]\boxed {\boxed {\sf About \ 37.1 \ grams \ of \ iodine }}[/tex]
Explanation:
To convert from atoms to grams, you must first convert atoms to moles, then moles to grams.
1. Convert Atoms to Moles
To convert atoms to grams, Avogadro's number must be used.
[tex]6.022*10^{23}[/tex]
This number tells us the number of particles (atoms, molecules, ions, etc.) in 1 mole. In this case, the particles are atoms of iodine.
[tex]\frac{6.022*10^{23} \ atoms \ I }{1 \ mol \ I}[/tex]
Multiply the given number of atoms by Avogadro's number.
[tex]1.76*10^{23} \ atoms \ I*\frac{6.022*10^{23} \ atoms \ I }{1 \ mol \ I}[/tex]
Flip the fraction so the atoms of iodine will cancel out.
[tex]1.76*10^{23} \ atoms \ I*\frac{ 1 \ mol \ I}{6.022*10^{23} \ atoms \ I}[/tex]
[tex]1.76*10^{23}* \frac{1 \ mol \ I}{6.022*10^{23} }[/tex]
Multiply so the problem condenses into 1 fraction.
[tex]\frac{1.76*10^{23} \ mol \ I}{6.022*10^{23} }[/tex]
[tex]0.2922617071 \ mol \ I[/tex]
2. Convert Moles to Grams
Now we must use the molar mass of iodine, which is found on the Periodic Table.
Iodine Molar Mass: 126.9045 g/molUse this mass as a fraction.
[tex]\frac{ 126.9045 \ g\ I }{ 1 \ mol \ I}[/tex]
Multiply this fraction by the number of moles found above.
[tex]0.2922617071 \ mol \ I*\frac{ 126.9045 \ g\ I }{ 1 \ mol \ I}[/tex]
Multiply. The moles of iodine will cancel.
[tex]0.2922617071 *\frac{ 126.9045 \ g\ I }{ 1 }[/tex]
The 1 as a denominator is insignificant.
[tex]0.2922617071 *{ 126.9045 \ g\ I }[/tex]
[tex]37.08932581 \ g \ I[/tex]
3. Round
The original measurement of 1.76*10^23 has 3 significant figures (1, 7, and 6). Therefore we must round our answer to 3 sig figs. For this answer, that is the tenths place.
[tex]37.08932581 \ g \ I[/tex]
The 8 in the hundredth place tells us to round the 0 up to a 1.
[tex]\approx 37.1\ g \ I[/tex]
There is about 37.1 grams of iodine in 1.76*10^23 atoms.
What is the relationship between the circulatory and respiratory systems?
A. They work together to store the waste that blood collects from the body.
B. The circulatory system provides oxygen that the respiratory system uses to fill the lungs
C. The respiratory system provides blood that the circulatory system uses to transport nutrients.
D. They work together to supply oxygen to tissues and rid the body of carbon dioxide
Answer:
The circulatory and respiratory systems work together to circulate blood and oxygen throughout the body. Air moves in and out of the lungs through the trachea, bronchi, and bronchioles. Blood moves in and out of the lungs through the pulmonary arteries and veins that connect to the heart
Explanation:
This should help you out
calculate the number of moles in 9 g of water
Answer:
= 0.5 moles of water
[tex]formular \: mass \: of \: water \: = (2 \times 1) + 16 = 18 \\ 18g \: of \: water \: are \: weighed \: by \: 1 \: mole. \\ 9g \: will \: be \: weighed \: by \: \frac{9 \times 1}{18} \\ = \frac{9}{18} moles \\ = 0.5 \: moles \: of \: water[/tex]
Answer:
0.5 mole
Explanation:
m(h2o)=2×1+16=18g
n=m÷Me=9÷18=0.5mole
What would be the effect on the polarity of the molecule formed when CCl4 has one Cl replaced by an H?
Answer:
It will become polar.
Explanation:
Look the image below. I know it's terrible, but I'll explain it:
ΔE is the electronegativity. The higher is the ΔE of a substance, the more it can attracts electrons.
Cl has more electronegativity than C and H. But it has, of course, the same amount of another Cl.
So, when we have a tetrahedral space disposition such as in the left draw, all the Cl cancels the others eletrostatic force. However, when we replace one Cl for H, then we will have a dipole moment pointing to the Cl who face the Hydrogen, as the right draw. The appearance of a resulting dipole indicates the existence of a polar compound.
What pressure, in atmospheres, is exerted by 0.325 mol of hydrogen gas in a 4.08 L container at 35*C?
Answer: 2.0 atm
Explanation:
PV = nRT
P- the pressure of the gas
V- the volume it occupies
n- the number of moles of gas
R- the universal gas content
T- the absolute temp. of the gas
The pressure, in atmospheres, is exerted by 0.325 mol of hydrogen gas in a 4.08 L container at 35°C is 7.03atm.
What is ideal gas equation?The ideal gas law relates the pressure, volume, temperature, and number of moles of a gas through the equation:
PV = nRT
where P is the pressure in atmospheres, V is the volume in liters (L), n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin (K).
T = 35°C + 273.15 = 308.15 K
Substituting the given values into the ideal gas law equation, we get:
P × 4.08 L = 0.325 mol × 0.08206 × 308.15 K
Simplifying and solving for P, we get:
P = (0.325 mol × 0.08206× 308.15 K) / 4.08 L
P = 7.03 atm
Thus, the pressure exerted by 0.325 mol of hydrogen gas in a 4.08 L container at 35°C is 7.03 atm.
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A certain compound has the following percent composition: 57.1% C, 4.8% H, and 38.l% O.
If the molar mass of this compound is 126 g/mol, what is the molecular formula?
Answer:
C₆H₆O₃
Explanation:
Calculation sequence:
% => grams => moles => reduce => empirical Ratio
Molecular multiple = Molecular Mass / Empirical Mass
C: => 57.1% => 57.1 g => 57.1/12 = 4.7583
H: => 4.8% => 4.8 g => 4.8/1 = 4.8000
O: => 38.1% => 38.1 g => 38.1/16 = 2.3813
TTL => 100% 100 g
Reduced Mole values =>
C : H : O => 4.7583/2.3813 : 4.8000/2.3813 : 2.3813/2.3813 => 2 : 2 : 1
∴ empirical formula => C₂H₂O
empirical formula weight => 2C + 2H + 1O = [2(12) + 2(1) + 1(16)] amu = 42 amu
molecular formula weight (given in problem) = 126 g/mole
The molecular formula is a whole number multiple of the empirical formula.
molecular multiple = 126 amu / 42 amu = 3
∴ molecular formula => (C₂H₂O)₃ => C₆H₆O₃