I NEED THIS NOW PLZ NO LINKS OR ILL REPORT
Which is an example of a chemical change? *
cutting paper in half
wax melting off a candle
the wick in a candle burning to ash
painting a wall blue
Answer:
the third one...........
Answer:
wax melting off a candle
Which formula contains 2 non metals
Answer:
The answer is SiO2
Explanation:
Because nonmetals are those who gain electrons and form ve ions
The boiling point of heavy water is?
Answer:
The boiling point of heavy water is 101.4C
please mark me brainlest pls
Answer: 101.42 Celsius
Explanation:
The boiling point of heavy water is 101.42 Celsius which is higher than the boiling point of normal water (100 Celsius)due to its higher molar mass
There are moles of Carbon if I have 2.25 x 1023 atoms of Carbon? A. 0.19 moles b. 5.38 moles c. 0.37 moles d. 2.67 moles
Answer:
c. 0.37 moles
Explanation:
To find the number of moles (n) in a certain number of atoms of a substance, we divide the number of atoms by Avogadro number (nA), which is 6.02 × 10²³ atoms.
That is,
n = number of atoms ÷ 6.02 × 10²³
According to this question, there are 2.25 x 10²³ atoms of carbon (C). The number of moles contained in this carbon is as follows:
n = 2.25 x 10²³ ÷ 6.02 × 10²³
n = 2.25/6.02 × 10 (23 - 23)
n = 0.374 × 1
n = 0.374moles
You have 350 mL of 3.4 M hydrochloric acid (HCl). How many grams of HCl gas are dissolved? Bonus: what is the volume of the HCl at STP?
Answer:
1. 43.44g of HCl
2. 26.67 L of HCl
Explanation:
1) Molarity of a solution = number of moles (n) ÷ Volume (V)
According to the provided information in this question,
V = 350 mL = 350/1000 = 0.350L
Molarity = 3.4 M
Using Molarity = n/V
3.4 = n/0.350
n = 3.4 × 0.350
n = 1.19mol
Using the formula below to calculate the mass of HCl;
mole = mass/molar mass
Molar mass of HCl = 1 + 35.5 = 36.5g/mol
mole = mass/MM
mass = 1.19 mol × 36.5g/mol
mass = 43.44g of HCl
2) At STP, HCl has a pressure of 1atm, a temperature of 273K
V = ?
n = 1.19 mol
R = 0.0821 Latm/molK
Using PV = nRT
V = nRT/P
V = 1.19 × 0.0821 × 273/1
Volume = 26.67L
How are moles and particles related? How could you find the number of particles in 4 moles of a substance?
Answer:
so in one mole of atom there are 6.02×10^23.
answers to B is 2.41×10^24
Explanation:
use this equation
number of particle=moles X 6.02×10^23
=4 X 6.02 ×10^23
=2.41×10^24
hope this make sense:)
The number of particles present in 4 moles of a substance is 24.088 particles.
What is moles?Moles is a unit to express the amount of any substance and in one mole of any substance 6.022 × 10²³ particles of that substance are present and this number is known as Avogadro's number.
As in 1 mole = 6.022 × 10²³ particles are present
In 4 moles = 4 × 6.022 × 10²³ = 24.088 particles are present
Hence, 24.088 particles are present in 4 moles.
To know more about Avogadro's number, visit the below link:
https://brainly.com/question/10614569
Identifying Changes of Matter
Which of these are chemical changes in matter? Check all tha
Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.
The fat adipose cells is broken down into fatty acids. Which pathway is involved in this process?
Answer:
the anwer is glycolysis
A student dissolves 0.75 mol NaCl in 3.55kg water. What is the molality of the resulting solution?
A) 10.32 m
B) 0.211 m
C) 68.2 m
*please help
Answer:
B) 0.211 M
Explanation:
What does the prefix trans-indicate?
The carbons on either side of the double bond are pointed in opposite directions.
2. Which element below would be the best choice when creating a covalent molecule with an
Oxygen atom?
A. Na
B. Mg
C. Ne
D. O
Determine the number of electrons and protons in the following element: Tc Group of answer choices 43 protons, 43 electrons 43 protons, 56 electrons 56 protons, 43 electrons 99 protons, 43 electrons
In lab, you calculate the density of an iron rod to be 7.30 g/cm3. The accepted value
for the density of iron is 7.80 g/cm3. What is your percent error?
Answer:
6.41 %Explanation:
The percentage error of a certain measurement can be found by using the formula
[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]
From the question
actual density = 7.80 g/cm³
error = 7.30 - 7.80 = 0.5
We have
[tex]p(\%) = \frac{0.5}{7.8} \times 100 \\ = 6.410256...[/tex]
We have the final answer as
6.41 %Hope this helps you
Lime is added to a lake to neutralize the effects of acid rain. The pH value of the
lake water rises from 4 to 7. What is the change in concentration of H+ ions in the
lake water?
Answer:
The change in concentration of H+ ions is -9.99×10⁻⁵
Explanation:
When pH rises, we talk about neutralization and, there is a decline in proton's concentration.
pH lower than 7 is acid
pH higher than 7 is basic
Protons are neutralized by hydroxides to make water as this:
H₃O⁺ + OH⁻ ⇄ H₂O
pH = - log [H₃O⁺]
[H₃O⁺] = 10^-pH
In conclussion: [H₃O⁺]₁ = 10⁻⁴ → 1×10⁻⁴
[H₃O⁺]₂ = 10⁻⁷ → 1×10⁻⁷
1×10⁻⁷- 1×10⁻⁴
The change in concentration of H+ ions is -9.99×10⁻⁵
Explain, in terms of particles, why liquid
iodine does not conduct electricity.
Answer:
Because iodine is a liquid, it has no melting point. Iodine is not an electrical conductor because each molecule consists of two iodine atoms connected by a covalent bond that cannot be stimulated sufficiently to transmit electrical energy.
Explanation:
brainlist???
Explanation:
Because in an aqueous solution of iodine, iodine atoms are joined to each other by simple covalent bonds. Thus, when excitation occurs, the strength of the covalent bond is too weak to be able to transfer electrons, thus lacking the ability to conduct electricity.
Will give brainliest
What is ozone depletion in simple words
Answer:
Ozone layer depletion is the thinning of the ozone layer present in the upper atmosphere. This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules. One chlorine can destroy 100,000 molecules of ozone. It is destroyed more quickly than it is created
Answer:
Ozone depletion, gradual thinning of Earth’s ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. The thinning is most pronounced in the polar regions, especially over Antarctica. Ozone depletion is a major environmental problem because it increases the amount of ultraviolet (UV) radiation that reaches Earth’s surface, which increases the rate of skin cancer, eye cataracts, and genetic and immune system damage. The Montreal Protocol, ratified in 1987, was the first of several comprehensive international agreements enacted to halt the production and use of ozone-depleting chemicals. As a result of continued international cooperation on this issue, the ozone layer is expected to recover over time.
A test light with an electrical resistance of 9.00 S2 draws a current of 1.50 A when
it is connected to an electrical source. How much power does the light use?
Answer:
20.25 W
Explanation:
Applying,
P = I²R.................... Equation 1
Where P = Power, I = current drawn by the test light, R = Resistance of the test light
From the question,
Given: I = 1.5 A, R = 9.00 Ω
Substitute these values into equation 1
P = (1.5²)(9)
P = 2.25×9
P = 20.25 W
249 g of potassium iodide, KI, is mixed with 496.5 g of lead(II) nitrate, Pb(NO3)2.
The equation of the reaction is represented below.
[Pb(NO3)2 = 331; KI = 166; PbI2 = 461, KNO3 = 101]
Calculate the number of moles of excess reagent left.
Give your answer to three significant figures.
Answer: The number of moles of excess reagent left is 0.750 moles
Explanation:
The number of moles is calculated by using the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
For KI:Given mass of [tex]KI[/tex] = 249 g
Molar mass of [tex]KI[/tex] = 166 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of KI}=\frac{249g}{166g/mol}=1.5mol[/tex]
For [tex]Pb(NO_3)_2[/tex]:Given mass of [tex]Pb(NO_3)_2[/tex] = 496.5 g
Molar mass of [tex]Pb(NO_3)_2[/tex] = 331 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of }Pb(NO_3)_2=\frac{496.5g}{331g/mol}=1.5mol[/tex]
The given chemical equation follows:
[tex]2KI+Pb(NO_3)_2\rightarrow 2KNO_3+PbI_2[/tex]
By stoichiometry of the reaction:
If 2 moles of KI reacts with 1 mole of lead(II) nitrate
So, 1.5 moles of KI will react with = [tex]\frac{1}{2}\times 1.5=0.75mol[/tex] of lead(II) nitrate
As the given amount of lead(II) nitrate is more than the required amount. Thus, it is present in excess and is considered as an excess reagent.
Thus, KI is considered a limiting reagent because it limits the formation of the product.
Moles of excess reactant ([tex]Pb(NO_3)_2[/tex]) left = [1.5 - 0.75] = 0.750 moles
Hence, the number of moles of excess reagent left is 0.750 moles
If a student has 125 mL of a 4.00 M CuSO4 solution and needs a 1.50 M solution, what volume do they need to dilute it to?
Answer:
333.3mL
Explanation:
Using the formula as follows:
C1V1 = C2V2
Where;
C1 = initial concentration (M)
C2 = final concentration (M)
V1 = initial volume (mL)
V2 = final volume (mL)
According to the information provided in this question,
C1 = 4.00M
C2 = 1.50M
V1 = 125mL
V2 = ?
Using C1V1 = C2V2
4 × 125 = 1.5 × V2
500 = 1.5V2
V2 = 500/1.5
V2 = 333.3mL
Therefore, the CuSO4 solution needs to be diluted to 333.3mL to make 1.50 M solution.
Predict the product(s) of the following neutralization reaction. Type the balanced the equation.
HNO3 + Ba(OH)2
Answer:
The products from the neutralization reaction are barium nitrate and water.
The balanced chemical equation is
2 [tex]HNO_{3}[/tex] + 1 [tex]Ba(OH)_{2}[/tex] --> 1 [tex]Ba(NO_3)_{2}[/tex] + 2 [tex]H_{2}O[/tex].
How or why does lead affect blood flow?
Answer:
lead causes vessels to constrict, limiting the space for blood to flow (compare the size of the red circles.) This narrowing increases blood pressure, forcing the heart to work harder.
Answer:
By mimicking calcium and increasing cell stress, lead causes vessels to constrict, limiting the space for blood to flow. This forces the heart to work harder because the narrowing increases blood pressure.
will give brainliest. In the Solubility lab, sugar was the and water was the solute / solution O solution / solute solute / solvent solvent/solute
Answer:
Sugar was the solute and water was the solvent.
Briefly discuss the following statement:
“The functional group concept is important in organizing the information of organic chemistry.”
Support your discussion by giving two chemical equations to illustrate the application of this concept for each of two functional groups.
Answer:
See explanation
Explanation:
The functional group is an atom, group of atoms or bond which is responsible for the chemical reactions of the members of a series of organic compounds.
The chemical properties of various groups of compounds in organic chemistry depends of the concept of functional groups. They help us to classify molecules into families or groups based on a common general molecular formula.
The nature of the functional group determines the overall chemical properties of the molecule such as polarity, water solubility, and so on. Chemical reactions occur only at the functional group.
For instance, for the reaction below, reaction occurs at the functional groups as follows;
CH3COOH + CH3OH -------> CH3COOCH3
Also, during amide formation, reaction occurs between the carbonyl chloride and an amine at the respective functional groups as shown;
CH3COCl + CH3NH2 -----> CH3CONHCH3 + HCl
S
O
sulfur dioxide
3. In liquid sulfur dioxide, which of the following types of intermolecular force(s) would be present?
London Dispersion Forces
Dipole-Dipole
II.
Hydrogen Bonding
IV
Covalent Bonds
A. I
B. I and II
C. I,II, and I
D. I, II, III, and IV
Answer:
B
Explanation:
B
HELP ASAP
Which of these 3 metals ,reacts more vigorously? Sodium, potassium or lithium *
a)Sodium reacts the most vigorously.
b)Potassium reacts the most vigorously.
c)Lithium reacts the most vigorously.
potassium reacts the most vigorously.
A 16.4L sample of NO2(S) has a density of 1.89 g/L. What is the mass of the sample NO2(s)?
A) 31.0 grams
B) 14.5 grams
C) 8.68 grams
D) 0.115 grams
Answer:
A. 31.0
Explanation:
Remember the formula [tex]Density = \frac{mass}{Volume}[/tex], or [tex]D=\frac{m}{V}[/tex].
The problem tells us that the density is 1.89 g/L, and that the volume is 16.4 L.(Remember that if the units are in some form of liters, it is volume, similar to how if the units are in grams, it is mass.)
Plug in the numbers for density and volume, and you will get:
[tex]1.89=\frac{m}{16.4}[/tex]
Then, multiply both sides by 16.4 to get:
m = 30.996 g ≈ 31.0 g
Hope this helps!
Make a flow chart on uses of metals and non metals
you have to make flow chart with explanation
Answer:
Metals:
1. Metals are strong than non metals
2. Metals can be formed in wires, thin sheets, utensils and any other heavy meachinary for industries.
3. Metals are used for building construction and used in many other manufacturers
Non Metals:
1. Non metals are less stronger than metals.
2. Non metals can be used for manufacturing bottles, toys, bags, files etc.
3. Non metals are used in making of bottles, jars, chairs etc.
Thank you.....
Have a good day.....
I need to know how to do this but if you could just answer it it's fine
Answer:
im not entirely sure what needs to be done but the 2NH3 is the product and the other half is the reactants .
if any elements are added to others it is the reactants
this is a breakdown of a compound because the arrow always indicates the direction of the reaction .
Which represents a balanced nuclear equation?
1) 23/11Na ——>24/11Mg+1/1H
2) 24/11Na ——>24/12Mg+0/-1e
3) 24/13Al ——>24/12Mg+0/-1e
4) 23/12Mg ——>24/12Mg+1/0n
Answer:
The correct option is 2.
Explanation:
In a nuclear reaction balanced we have that:
1. The sum of the mass number (A) of the reactants (r) is equal to the sum of the mass number of the products (p) [tex] \Sigma A_{r} = \Sigma A_{p} [/tex]
2. The sum of the atomic number (Z) of the reactants is also equal to the sum of the atomic number of the products [tex]\Sigma Z_{r} = \Sigma A_{p}[/tex]
So, let's evaluate each option.
1) [tex]^{23}_{11}Na \rightarrow ^{24}_{11}Mg + ^{1}_{1}H[/tex]
The mass number of the reactant is:
[tex]A_{r} = 23 [/tex]
The sum of the mass number of the products is:
[tex] A_{p} = 24 + 1 = 25 [/tex]
This is not the correct option because it does not meet the first condition ([tex] \Sigma A_{r} = \Sigma A_{p}[/tex]).
2) [tex]^{24}_{11}Na \rightarrow ^{24}_{12}Mg + ^{0}_{-1}e[/tex]
The mass number of the reactant and the products is:
[tex]A_{r} = 24 [/tex]
[tex] A_{p} = 24 + 0 = 24 [/tex]
Now, the atomic number of the reactants and the products are:
[tex]Z_{r} = 11 [/tex]
[tex] Z_{p} = 12 + (-1) = 11 [/tex]
This nuclear reaction is balanced since it does meet the two conditions for a balanced nuclear equation, ([tex] \Sigma A_{r} = \Sigma A_{p}[/tex] and [tex] \Sigma Z_{r} = \Sigma Z_{p}[/tex]).
3) [tex]^{24}_{13}Al \rightarrow ^{24}_{12}Mg + ^{0}_{-1}e[/tex]
The mass number of the reactant and the products is:
[tex]A_{r} = 24 [/tex]
[tex] A_{p} = 24 + 0 = 24 [/tex]
Now, the atomic number of the reactants and the products are:
[tex]Z_{r} = 13 [/tex]
[tex] Z_{p} = 12 + (-1) = 11 [/tex]
This reaction does not meet the second condition ([tex] \Sigma Z_{r} = \Sigma Z_{p}[/tex]) so this is not a balanced nuclear equation.
4) [tex]^{23}_{12}Mg \rightarrow ^{24}_{12}Mg + ^{1}_{0}n[/tex]
The mass number of the reactant and the products is:
[tex]A_{r} = 23 [/tex]
[tex] A_{p} = 24 + 1 = 25 [/tex]
This reaction is not a balanced nuclear equation since it does not meet the first condition ([tex] \Sigma A_{r} = \Sigma A_{p}[/tex]).
Therefore, the correct option is 2.
I hope it helps you!
Is salt pure or impure
Answer:
pure
Explanation:
because there no additional substance