Answer:
See below
Explanation:
First, you need to know what a significant figure means.
The significant figures in a measurement consist of all the certain digits in one measurement, including one uncertain or estimated digit.
With that being said, the second thing we need to do is to correct the exercise. According to an external source, the exercise is the following:
a) x = 17.2 + 65.18 - 2.4
In this case, we can say that 17.2 and 2.4 has the uncertain digit at the end, but in 65.18 it's the 8. Therefore, when we make the sum of all of this we have:
x = 17.2 + 65.18 - 2.4 = 79.98
The last digit is the uncertain digit, therefore, we won't include this digit. So the final result would have 3 significant figure. However 8 surpass 5, and hence, we should approximate our result. Then our final result is:
x = 80.0
b) x = 13.0217 / 17.10
The last digit of the 13, is the uncertain. So, doing this:
x = 13.0217 / 17.10 = 0.761502924
With the correct significant figure, this would be only 4 so:
x = 0.7615
c) x = (0.0061020)*(2.0092)*(1200.00)
Applying the same principle as before:
x = (0.0061020)*(2.0092)*(1200.00) = 14.712
Hope it helps
There are many important laws and theories in science. Which of the following is a law of scienco?
A living thing is made of at least one cell.
An atom is made of electrons orbiting a nucleus.
Gravity will pull two objects toward each other.
Natural selection will change species to fit their environments.
Answer: Gravity will pull two objects together.
Explanation: It’s newton’s 1 and kinda his 2 law.
Humans have three types of cone cells in their eyes, which are responsible for color vision. Each type absorbs a certain part of the visible spectrum. Suppose a particular cone cell absorbs light with a wavelength of 519.nm. Calculate the frequency of this light. Round your answer to 3 significant digits.
Answer:
5.78 × 10¹⁴ Hz
Explanation:
Step 1: Given and required data
Wavelength of this light (λ): 519. nmFrecquency of this light (ν): ?Speed of light (c): 3.00 × 10⁸ m/sStep 2: Convert "λ" to meters
We will use the conversion factor 1 m = 10⁹ nm.
519. nm × 1 m/10⁹ nm = 5.19 × 10⁻⁷ m
Step 3: Calculate the frecquency of this light
We will use the following expression.
c = λ × ν
ν = c/λ
ν = (3.00 × 10⁸ m/s)/5.19 × 10⁻⁷ m
ν = 5.78 × 10¹⁴ s⁻¹ = 5.78 × 10¹⁴ Hz
Help answer this if you know it thank you!
Answer:
evolution
Explanation:
Answer:
because bird species are reproduced sexually
so there would be some variations in every generation.
that's why birds could be different from their ancestors.
A 6.40 g sample of a compound is burned to produce 8.37 g CO_2, 2.75 g H_2O, 1.06 g N_2, and 1.23 g SO_2. What is the empirical formula of the compound? Give your answer in the form C#H#N#O#S# where the number following the element’s symbol corresponds to the subscript in the formula. (Don’t include a 1 subscript explicitly).
The empirical formula :
C₁₀H₁₆N₄SO₇
Further explanationGiven
6.4 g sample
Required
The empirical formula
Solution
mass C :
= 12/44 x 8.37 g
= 2.28
mass H :
= 2/18 x 2.75 g
= 0.305
mass N = 1.06
mass S :
= 32/64 x 1.23
= 0.615
mass O = 6.4 - (2.28+0.305+1.06+0.615) = 2.14 g
Mol ratio :
= C : H : N : S : O
= 2.28/12 : 0.305/1 : 1.06/14 : 0.615/32 : 2.14/16
= 0.19 : 0.305 : 0.076 : 0.019 : 0.133 divided by 0.019
= 10 : 16 : 4 : 1 : 7
The empirical formula :
C₁₀H₁₆N₄SO₇
is C5H10 ionic or covalent?
Consider Example 12.10. Suppose the experiment is repeated with 0.032 mol of helium instead with everything else staying the same, what is the amount of heat required now to achieve that process
Answer:
120 extracted from the gas
Explanation:
The amount of heat required now to achieve that process is 60 J of heat added to the gas.
Heat required to achieve the processThe amount of heat required to achieve the process is calculated as follows;
[tex]E = \frac{3}{2} nR\Delta T[/tex]
where;
n is number of moles of the helium gas = 0.032 moleR is ideal gas constant = 8.314 J/mol.KΔT is change in temperature (from example 12.10) = 450 K - 300 K = 150 K[tex]E = \frac{3}{2} \times 0.032 \times 8.314 \times (150)\\\\E = 60 \ J[/tex]
Thus, the amount of heat required now to achieve that process is 60 J of heat added to the gas.
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Question 6 of 10
What is ethane?
A. An alkane
B. An alkene
C. A polymer
D. An alkyne
Answer:
An Alkane
Explanation:
Formula of ethane is CH3-CH3
Answer:
Ethane is the second member of
An alkane
A friend of yours went panning for gold last weekend and found a nugget that appears to be gold. With your newfound scientific prowess, you set out to determine if it is really gold. Your tests show that the nugget has a mass of 7.6 g. Immersing the nugget in water raised the volume from 7.22 mL to 8.06 mL. The density of gold is 19.32 g/cm3. What will you tell your friend
Answer:
both density is different so we can say nugget is not made by gold
Explanation:
given data
mass m = 7.6 g
volume v = 7.22 mL to 8.06 mL
density of gold = 19.32 g/cm³
solution
we know that if there is when there is density of gold = density of nugget than we can say it is gold
so here
d = [tex]\frac{m}{v}[/tex] ........1
here v = (8.06 - 7.22) = 0.84 mL
put here value in eq 1
d = [tex]\frac{7.6}{0.84}[/tex]
d = 9.047 g/ml
so here density is different so we can say it is not by gold
What is the correct name of this isotope? *
oxygen - 16
oxygen - 8
oxygen - 24
The correct name of this isotope : Oxygen - 16
Further explanationGiven
Isotope : ₈¹⁶O
Required
The correct name
Solution
The elements in nature have several types of isotopes
Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In the following element notation,
[tex]\large {{{A} \atop {Z}} \right X}[/tex]
X = symbol of elemental atom
A = mass number
Z = atomic number
The isotope name is usually followed by its mass number, so the symbol above can be expressed as oxygen - 16
Molecules move faster and farther apart when state changes from ? to ?
The molecules move faster and farther apart when the state changes from the liquid state to the gaseous state.
What are states of matter?The matter exists in different forms in nature. Some substances have a fixed shape like wood and stone and can flow, take the shape of their container such as water, while there are forms of matter that do not have certain shapes or sizes.
In solids, the molecules are closely packed and thus solids have a rigid structure. The compact packing of solids means that the molecules are very close to each other and the molecules do not show movement. The kinetic energy of molecules in the solid is the least.
In liquids, the molecules are some distance away from each other and they show movements. Since the molecules in liquid show significant movement, they have some kinetic energy. The kinetic energy of molecules in the liquid is greater than that of solids.
In gases, the molecules are farther from each other and thus their molecules show large amounts of movement. The kinetic energy in gases is the greatest in comparison to solids and liquids.
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Can soft drinks be part of a healthy diet?
Answer:
yes, but its better to drink water
Explanation:
identified the nucleus that is found in an item that has a stable valance electron configuration
Answer:
Nucleus 3 i believe
A student prepared several aqueous sodium chloride (NaCl) solutions to observe boiling point elevation at various molal concentrations, however, several errors were made throughout the procedure. Determine whether these errors would cause the observed boiling point to be increased or decreased relative to the expected boiling point, based on the procedure, or have no effect on the experimental results.
The question is incomplete, the complete question is;
A student prepared several aqueous sodium chloride (NaCl) solutions to observe boiling point elevation at various molal concentrations, however, several errors were made throughout the procedure. Determine whether these errors would cause the observed boiling point to be increased or decreased relative to the expected boiling point, based on the procedure, or have no effect on the experimental results.
* The flask is washed with water but not thoroughly dried before preparing the solution
* The mass of NaCl used to prepare the solution is 5.400 grams instead of 4.400 grams
* Some of the prepared solution splashes out of the flask prior to observation of the boiling point
* When making the salt solution, 55.0 milliliters of water is added instead of 50.0 milliliters
Answer:
The flask is washed with water but not thoroughly dried before preparing the solution - decrease
The mass of NaCl used to prepare the solution is 5.400 grams instead of 4.400 grams
-increase
Some of the prepared solution splashes out of the flask prior to observation of the boiling point- have no effect
When making the salt solution, 55.0 milliliters of water is added instead of 50.0 milliliters- decrease
Explanation:
If the flask is washed but not dried, then the solution will be further diluted than expected. As a result of this further dilution, the observed boiling point will be less than the expected boiling point because the boiling point depends on the solution's concentration.
If more solute is added than expected, the concentration of the solution is increased and the boiling point also increases above the expected boiling point due to the increase in amount of solute present.
If some of the solution splashes out of the flask prior to boiling, the boiling point is not affected because the concentration of the solution was not altered. The boiling point only changes when the concentration of the solution is changed.
If 55 ml of water is added instead of 50 ml, the solution is now more dilute than expected thereby reducing the concentration of the solution and the boiling point. Remember that, as the concentration of the solution decreases, the boiling point decreases accordingly.
three molecules the cells need and why?
Identify the term that matches each definition.
The front vent of a fume hood, which helps maintain proper air circulation____.
The horizontal, flat area of a fume hood upon which experiments are carried out____.
A characteristic that describes substances that evaporate readily, producing large amounts of vapors____.
The glass panel in front of the fume hood that shields the user from fumes and other hazard_____.
A. Airfoil.
B. Sash.
C. Work surface.
D. Volatile.
Answer:
A,
C.
D.
B.
Explanation:
The front vent of a fume hood that assists and maintain proper air circulation is Airfoil
The horizontal flat surface area of the fume hood where experiments are being carried out is Work Surface.
The main characteristics which demonstrate and describes how substances evaporate rapidly and readily into the thin air while producing a huge amount of vapor is known as Volatile
In front of the fume hood, lies the glass panel whose main purpose is to shield the user from the hazardous substance. This glass panel is known as the Sash.
3. The picture below is an example of a _________ _________. (Answer is 2 words)
Answer:
I can't see any picture?????
If it takes 38.70cm of 1.90M NaOH to neutralize 10.30cm of H2SO4 in a battery, what is the molarity of H2SO4?
Answer:
The molarity of the acid, H₂SO₄ is 3.57 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O
From the balanced equation above,
Mole ratio of the acid, H₂SO₄ (nₐ) = 1
Mole ratio of the base, NaOH (n₆) = 2
Finally, we shall determine the molarity of the acid, H₂SO₄. This can be obtained as follow:
Volume of base, NaOH (V₆) = 38.70 cm³
Molarity of base, NaOH (M₆) = 1.90M
Volume of acid, H₂SO₄ (Vₐ) = 10.30 cm³
Molarity of acid, H₂SO₄ (Mₐ) =?
MₐVₐ / M₆V₆ = nₐ/n₆
Mₐ × 10.3 / 1.9 × 38.70 = 1/2
Mₐ × 10.3 / 73.53 = 1/2
Cross multiply
Mₐ × 10.3 × 2 = 73.53 × 1
Mₐ × 20.6 = 73.53
Divide both side by 20.6
Mₐ = 73.53 / 20.6
Mₐ = 3.57 M
Thus, the molarity of the acid, H₂SO₄ is 3.57 M
A sample of PCl5 weighting 2.69 gram was placed in 1.00 Litter container and completely vaporized at 250C. The pressure observed at that temperature was 1.00 atm. The possibility exists that some of the PCl5 dissociated according to PCl5 (g) ! PCl3 (g) Cl2 (g) . What must be the partial pressures of PCl5 PCl3 and Cl2 under these experimental conditions
Answer:
Partial pressures:
PCl₅ = 0.558 atm
PCl₃ = 0.22 atm
Cl₂ = 0.22 atm
Explanation:
From the given information:
The number of moles of PCl₅ associated with the evaporation is:
[tex]n_{PCl_5}= \dfrac {weight \ of \ PCl_5} {M.Wt. \ of \ PCl_5}[/tex]
[tex]n_{PCl_5}= \dfrac {2.69 \ g} {208.5 \ g/mol}[/tex]
[tex]n_{PCl_5}= 0.013 \ mol[/tex]
Temperature of the gas = 250° C = (250 + 273.15) K
= 523.15 K
Using the Ideal gas equation to determine the pressure exerted by the completely vaporized PCl₅
PV = nRT
[tex]P = \dfrac{nRT}{V}[/tex]
[tex]P = \dfrac{0.0013 \ mol \times 0.082 \ Latm^0 K^{-1} . mol ^{-1} \times 523.15 \ K}{1.0 \ L}[/tex]
P = 0.558 atm
Thus, at 250° C, decomposition of PCl₅ occurs.
In the container, PCl₅ decomposes to PCl₃ and Cl₂.
i.e.
[tex]PCl_{5(g)} \to PCl_{3(g)}+ Cl_{2(g)}[/tex]
Using Dalton's Law:
[tex]P_{total } =P_1 + P_2+P_3 +...[/tex]
[tex]P_1 = P_{Total} \times X_1[/tex]
where;
X = mole fraction
Then, the total no. of moles in the container is:
[tex]n = \dfrac{PV} {RT}[/tex]
[tex]n = \dfrac{1\ atm \times 1.0\ L}{0.0821 \ L \ atm \ K^{-1}.mol \times 523.15\ K}[/tex]
n = 0.023 mol
Now, the container contains a total amount of 0.023 mol where initially 0.013 mol are that of PCl₅ and remaining 0.005 mol of PCl₃ and 0.005 mol of Cl₂.
Thus, the partial pressure of PCl₃ is:
[tex]P__{PCL_3} }= P_{total} \times \dfrac{no. \ of \ moles \ of PCl_5}{total \ no. \ of \ moles}[/tex]
[tex]P__{PCL_3}} = 1 \ atm \times \dfrac{0.005}{0.023}[/tex]
[tex]P__{PCL_3}} = 0.22 \ atm[/tex]
Thus, since the no of moles of PCl₃ and Cl₂ are the same, then the partial pressure for Cl₂ is = 0.22 atm
Magnesium reacts with iron(III) chloride to form magnesium chloride (which can be used in fireproofing wood and in disinfectants) and iron. A mixture of 43.5 g Mg and 247 g iron(III) chloride is allowed to react. What is the limiting reactant and what is the mass, in grams, of the excess reactant remains
Answer:
Mg is the limiting reactant.
52.9 g of FeCl₃, remains after the reaction is complete.
Explanation:
First of all, we state the reaction's equation:
3Mg (s) + 2FeCl₃ (aq) → 2Fe (s) + 3MgCl₂ (s)
We determine the mol of each reactant:
43.5 g . 1mol / 24.3g = 1.79 mol of Mg
247 g . 1mol/ 162.2g = 1.52 mol of Iron (III) chloride.
Ratio is 2:3. 2 mol of chloride need 3 moles of Mg to react,
Then 1.52 moles will react with (1.52 . 3) /2 = 2.29 moles
We have 1.79 moles of Mg and we need 2.29, so the limiting reactant is the Mg.
We confirm the chlorine as the excess reactant:
3 moles of Mg need 2 moles of FeCl₃ to react:
1.79 moles of Mg will react to (1.79 . 2) /3 = 1.19 moles of FeCl₃
We have 1.52 moles of FeCl₃ and we only need 1.19, so it is ok, we said that the FeCl₃ is the excess.
After the reaction goes complete, (1.52 - 1.19) moles of FeCl₃ remains.
1.52 - 1.19 = 0.33 moles. We convert them to mass:
0.33 mol . 162.2g /1mol = 52.9 g
PLEASE HELP! this is due soon!!
Answer:
The right one.
Explanation:
The right one looks like it is getting the most sun.
A solution with a pH of 11 has a [H] of:
11
1x 10-3
1x 10-11
1x 1011
1x 103
Answer:
1 x 10⁻¹¹moldm⁻³
Explanation:
Given parameters:
pH of the solution = 11
Unknown:
[H] = ?
Solution:
The hydrogen ion concentration is unknown.
From:
PH = - log[H⁺]
So;
11 = -log[H⁺]
[H⁺] = 1 x 10⁻¹¹moldm⁻³
Which statement is always true about conversation of matter?
The mass of a system does not change during a chemical reaction
If a solid forms the mass of a system increases
If a gas forms the mass of a system decreases
The mass of a system changes when a substance changes from liquid to gas, but it does not change in a chemical reaction
Answer:
The mass of a system does not change during a chemical reaction
Explanation:
Correct Answers
The best known Lepton is the _________________.
a
electron
b
boson
c
fermion
d
hadron
e
neutron
f
proton
Answer:
Electron (e-)
Explanation:
An electron is just one of the fundamental particles
Answer:heyyyy
Explanation:
. The level of mercury in a stream was suspected to be above the minimum considered safe (1 part per billion by weight). And analysis indicated that the concentration was 0.68 parts per billion. Assume a density of 1.0 g/mL and calculate the molarity of mercury in the stream.
Answer:
3.39x10⁻⁹ M
Explanation:
Let's assume we have 1 mL of the stream. With a density of 1.0 g/mL, we would have 1 g of the stream.
Now we calculate the mass of mercury present in 1 g of the stream, using its given concentration (0.68 ppb):
ppb = ng Mercury / g stream0.68 ppb = ng Hg / 1 gMass of mercury = 0.68 ngNow we convert that mass into moles, using mercury's atomic mass:
0.68 ng = 0.68 x 10⁻⁹ g0.68 x 10⁻⁹ g ÷ 200.59 g/mol = 3.39x10⁻¹² molFinally we calculate the molarity of mercury, as we know that there are 3.39x10⁻¹² Hg moles in 1 mL of the stream:
1 mL = 0.001 LMolarity = 3.39x10⁻¹² mol / 0.001 L = 3.39x10⁻⁹ M
_H2+_Cl2->_HCl fill in the blanks if necessary.
Answer:
H₂ + Cl₂ → 2HCl
Explanation:
The given reaction expression is shown below:
H₂ + Cl₂ → HCl
We are to balance this given reaction expression.
Let us do this mathematically;
aH₂ + bCl₂ → cHCl
Conserving H : 2a = c
Cl: 2b = c
Now, let a = 1, c = 2 , b = 1
So:
H₂ + Cl₂ → 2HCl
Determine where each type of cleaning solution should be discarded after use. Solvent used to rinse chemicals out of a beaker ______Acid solution used to clean a crucible _________Water used to rinse detergent out of a flask ________
Answer:
Acidic solution used to clean a crucible
Explanation:
This liquid dissolves alcoholic solvents such as crucible, that is why it was selected as the ideal for cleaning.
Although it would be ideal to know in detail which chemical compound is the one you want to clean so that the cleaning technique has better effectiveness.
WASTE CONTAINER refers to the solvent used to rinse chemicals out of a beaker, and it also refers to the acid solution used to clean a crucible. Water used to rinse the detergent out of a flask refer to the SINK.
The disposal containers in a lab can be used for recycling, disposal of trash, glassware disposal box, sharp box, etc.A waste container is a container usually used to dispose of waste in a laboratory, which may be made of plastic.Moreover, a laboratory sink can be used to wash tools and/or hands without the hazard of damaging the health or the sink.In conclusion, WASTE CONTAINER refers to the solvent used to rinse chemicals out of a beaker, and it also refers to the acid solution used to clean a crucible. Water used to rinse the detergent out of a flask refer to the SINK.
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When measuring the volume of a liquid, how would sample size (e.g., using a 10 mL graduated cylinder vs. a 100 mL graduated cylinder to measure out 70 mL of a liquid) affect the absolute error and percentage error in the measured values of mass and volume and therefore the density
Answer:
Explanation:
From the given information:
The accuracy depends on the internal diameter of the cylinder. The cylinder with the least internal diameter is obviously more precise.
Let's assume 1% is the error of measurement.
Then, to measure 70 mL from 10 mL cylinder
The error = [tex]10 \times \dfrac{1}{100} \times 7[/tex]
= 0.7 mL
However; for a 100 mL cylinder, the error = 1 mL
Now,
The total volume for 10 mL = (70 + 0.7) = 70.7 mL
The total volume for 100 mL = (70 + 1 ) = 71 mL
Suppose the density (d) is same for both
Then;
the mass of 10 mL = ( d × 70.7) g
the mass pf 100 mL = (d × 71) g
Thus, the mass of 100 mL is greater than that of 10 mL.
Sulfurous acid reacts with barium hydroxide.
Answer:
Ba(OH)2 + H2SO3 = BaSO3 + H2O -
Explanation:
What is wrong with the chemical reaction written below?
REACTANT(S)
PRODUCTS
Magnesium + Chlorine ------>
Magnesium Chloride
12 g Magnesium
+
8 g Chlorine
25 g Magnesium Chloride
a) Magnesium will never react with chlorine
b) The mass of your total product is greater than your total reactants
c) The name of the product is incorrect
d) Nothing is wrong with the above reaction-it is perfectly correct as written!
Answer:
b) The mass of your total product is greater than your total reactants
Explanation:
Mass of reactants is 20 and product is 25 which never occurrs in real
A clone has _________ chromosomes as its parent.
A. Half the number of
B. The same exact
C. double the number of
D. half of the same
Answer:
B. The same exact
Explanation:
I think B because in order to be a clone of your parent you have to have the exact same DNA and chromosomes.
Hope this helps :D
A clone has the same exact chromosomes as its parent.
CLONING:
Cloning is a genetic procedure in which identical copies of a cell or organism is made. Cloning can be done naturally or artificially, however, it follows the process of mitosis. In cloning, the genetic content of a parent cell is used as a template to replicate another cell or organism. Examples of cloning are biological twins, vegetative reproduction in plants etc. Therefore, a clone has the same exact chromosomes as its parent.Learn more at: https://brainly.com/question/12483409?referrer=searchResults