petrol pump attendant close the full fuel cap quickly after filling petrol in vehicles what could be the reason
Answer:
Below.
Explanation:
For safety reasons.
The fuel is very volatile and the vapour is very inflammable.
Petrol pump attendants close the fuel cap quickly to prevent the evaporation of volatile gasoline, to minimize the risk of overfills and spills, and to maintain the integrity of air gaps in fuel tanks which allows for safe expansion and contraction of the fuel.
When a petrol pump attendant quickly closes the fuel cap after filling a vehicle's tank, it is primarily to prevent the evaporation of gasoline. Gasoline is a volatile, complex mixture of hydrocarbon compounds that can easily vaporize at normal temperatures, leading to a significant loss of fuel due to evaporation. This is why the fuel cap must be securely fastened immediately after refueling.
Moreover, overfilling tanks is a safety hazard that can lead to spills, and in the presence of an ignition source, there is a potential for explosions causing serious property damage, environmental issues, and injury. Therefore, it is also important to avoid over-filling and ensure that fuel levels are appropriate, and safety measures such as securing the cap promptly are critical.
Additionally, fuel tanks, including underground storage tanks (USTs), are designed with air gaps to allow for the expansion and contraction of the liquids. This prevents the leaking of gasoline around the cap or the bursting of the tank. Closing the fuel cap tightly and quickly helps maintain the integrity of these air gaps and prevents the escape of gasoline vapors into the atmosphere.
Element X and element Y have a difference in electronegativity of 1:2 will the bond XY be covalent or ionic
Answer:
The bond between XY is Covalent
Explanation:
Types of Bonds can be predicted by either identifying the two bonding elements or by calculating the difference in electronegativity.
The two atoms bonded to each other can be both metals, non-metals or one metal and the other non-metal. If both are metals then we can say that the bond is metallic. If both are non-metals then we can say that the bond is nonpolar and covalent. If one is metal and the other is non-metal then the bond between them will be ionic.
Secondly,
If, Electronegativity difference is,
Less than 0.4 then it is Non Polar Covalent Bonding
Between 0.4 and 1.7 then it is Polar Covalent Bonding
Greater than 1.7 then it is Ionic Bonding
As, the element X and Y have the electronegativity difference of 1.2 (which is less than 1.7 and greater than 0.4) therefore, we can say that the bond between them is covalent and it is polar in nature.
Final answer:
The bond between element X and Y with a significant difference in electronegativity of 1:2 is likely ionic, especially if the difference is greater than 1.8. Exact values of electronegativity and the types of elements involved would provide a more accurate determination.
Explanation:
The question concerns whether a bond between element X and element Y with a difference in electronegativity of 1:2 will be covalent or ionic. The electronegativity difference helps to predict the bond type. A higher electronegativity difference indicates more ionic character, whereas a lower difference suggests a covalent bond. Since '1:2' is not a standard way to express electronegativity, we can assume it refers to a ratio indicating a significant difference, suggesting that the bond may be ionic. However, the exact nature of the bond would better be determined if the exact electronegativity values were provided, considering that usually electronegativity differences greater than 1.8 lead to an ionic bond.
Additionally, the types of elements involved can provide a clue as to the bond type. For instance, a bond between a metal and a nonmetal often results in an ionic bond whereas a bond between two nonmetals is more likely to be covalent. Bonds with intermediate electronegativity differences are typically polar covalent, where the shared electrons are drawn more towards the more electronegative atom.
What’s the oxidation state of Se in H2SeO3
Answer:
The oxidation states are as follows:
+1 for each H, -2 for each O,
+4 for Se
Explanation: I hope this attachment helps!!
A chemist combined chloroform (CHCl3) and acetone (C3H6O) to create a solution where the mole fraction of chloroform is 0.187. The densities of chloroform and acetone are 1.48 g/mL and 0.791 g/mL, respectively.
Calculate the molarity and molality of the solution.
Answer:
[tex]\large \boxed{\text{c = 2.50 mol/L; b = 3.96 mol/kg }}[/tex]
Explanation:
1. Molar concentration
Let's call chloroform C and acetone A.
Molar concentration of C = Moles of C/Litres of solution
(a) Moles of C
Assume 0.187 mol of C.
That takes care of that.
(b) Litres of solution
Then we have 0.813 mol of A.
(i) Mass of each component
[tex]\text{Mass of C} = \text{0.187 mol C} \times \dfrac{\text{119.38 g C}}{\text{1 mol C}} = \text{22.32 g C}\\\\\text{Mass of A} = \text{0.813 mol A} \times \dfrac{\text{58.08 g A}}{\text{1 mol A}} = \text{47.22 g A}[/tex]
(ii) Volume of each component
[tex]\text{Vol. of C} = \text{22.32 g C} \times \dfrac{\text{1 mL C}}{\text{1.48 g C}} = \text{15.08 mL C}\\\\\text{Vol. of A} = \text{47.22 g A} \times \dfrac{\text{1 mL A}}{\text{0.791 g A}} = \text{59.70 mL A}[/tex]
(iii) Volume of solution
If there is no change of volume on mixing.
V = 15.08 mL + 59.70 mL = 74.78 mL
(c) Molar concentration of C
[tex]c = \dfrac{\text{0.187 mol}}{\text{0.07478 L}} = \textbf{2.50 mol/L }\\\\\text{ The molar concentration of chloroform is $\large \boxed{\textbf{2.50 mol/L}}$}[/tex]
2. Molal concentration of C
Molal concentration = moles of solute/kilograms of solvent
Moles of C = 0.187 mol
Mass of A = 47.22 g = 0.047 22 kg
[tex]\text{b} = \dfrac{\text{0.187 mol}}{\text{0.047 22 kg}} = \textbf{3.96 mol/kg }\\\\\text{The molal concentration of chloroform is $\large \boxed{\textbf{3.96 mol/kg}}$}[/tex]
The molarity and molality of a solution can be calculated given the mole fraction of two components, their densities, and molar masses. The acetone will have a larger volume in the solution due to its higher mole fraction. By obtaining the masses of each component for a given volume, the number of moles of each can be calculated and used to compute molarity and molality.
Explanation:The subject of this question involves the calculation of molarity and molality of a solution. First, let us understand what molarity and molality mean. Molarity (M) is the number of moles of solute per liter of solution. Molality (m) is the number of moles of solute per kilogram of solvent.
Given that the mole fraction of chloroform (Cx) is 0.187, the mole fraction of acetone (Ay) can be calculated as 1 - Cx = 1 - 0.187 = 0.813. From the densities and molar masses of chloroform (119.38 g/mol) and acetone (58.08 g/mol), we can convert these to masses for a given volume. Assuming a total volume of 1 L for the solution, we know that the acetone has more volume due to its mole fraction. We can find the number of moles of each component from these masses, and finally, compute the molarity (moles/L) and the molality (moles/kg).
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If a car goes from 20 miles per hour to 10 miles per hour in 5 seconds, find its acceleration.
A)
2 miles per hour per second
B 5 miles per hour per second
C)
-2 miles per hour per second
10-mites per reuf per second
can you guys help me with my homework?
Many plants are poisonous because their stems and leaves contain oxalic acid, H2C2O4, or sodium oxalate, Na2C2O4; when ingested, these substances cause swelling of the respiratory tract and suffocation. A standard analysis for determining the amount of oxalate ion, C2O42-, in a sample is to precipitate this species as calcium oxalate, which is insoluble in water. Write the net ionic equation for the reaction between sodium oxalate and calcium chloride, CaCl2, in aqueous solution. (Use the lowest possible coefficients. Omit states-of-matter in your answer.)
Answer:
H₂C₂O₄ + Ca²⁺ ⟶ CaC₂O₄ + 2H⁺
Explanation:
There are three steps you must follow to get the answer.
You must write the:
Molecular equation Ionic equation Net ionic equation
1. Molecular equation
H₂C₂O₄(aq) + CaCl₂(aq) ⟶ CaC₂O₄(s) + 2HCl(aq)
2. Ionic equation
You write the molecular formulas for the weak electrolytes and solids, and you write the soluble ionic substances as ions.
H₂C₂O₄(aq) + Ca²⁺(aq) + 2Cl⁻(aq) ⟶ CaC₂O₄(s) + 2H⁺(aq) + 2Cl⁻(aq)
3. Net ionic equation
To get the net ionic equation, you cancel the ions that appear on each side of the ionic equation.
H₂C₂O₄(aq) + Ca²⁺(aq) + 2Cl⁻(aq) ⟶ CaC₂O₄(s) + 2H⁺(aq) + 2Cl⁻(aq)
The net ionic equation is
H₂C₂O₄ + Ca²⁺ ⟶ CaC₂O₄ + 2H⁺
The net ionic equation is; Ca^2+ (aq) + C2O4^2-(aq) -------> CaC2O4(s)
First we must put down the molecular equation as follows;
Na2C2O4(aq) + CaCl2(aq) ------> 2NaCl(aq) + CaC2O4(s)
The total ionic equation is;
2Na^+(aq) + Cl^- (aq) + Ca^2+ (aq) + C2O4^2-(aq) -------> 2Na^+(aq) + Cl^- (aq) + CaC2O4(s)
The net ionic equation is;
Ca^2+ (aq) + C2O4^2-(aq) -------> CaC2O4(s)
The spectator ions in this reaction are Na^+ and Cl^-, they appear on both sides of the reaction equation and they do not appear in the final net ionic equation.
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Calculate the number of moles of Mg(NO3)2 consisting of 8.428 x 10^23 formula units of
Mg(NO3)2
Answer: 1.4 moles Mg(NO3)2
Explanation: Solution attached:
Convert the formula units of Mg(NO3)2 to moles using the Avogadro's number.
When nitrous oxide is converted to nitrogen and oxygen, what is the term used to describe the oxygen atoms formed?
A) Reactants
B) Products
C) Intermediates
D) Activated complexes
Answer:
B) Products
Explanation:
Nitrous oxide is colorless gas.
It is also called laughing gas.
It is used in medicine specially in pain relief.
It is also used by dentists.
Chemical equation:
2N₂O → 2N₂ + O₂
Here nitrous oxide is converted into nitrogen and oxygen. Nitrous oxide is reactant and nitrogen and oxygen are product.
The given reaction is decomposition reaction of nitrous oxide.
Decomposition reaction:
It is the reaction in which one reactant is break down into two or more product.
AB → A + B
Answer:
intermediates
Explanation:
Hey gradpoint :)
describe two ways that thermal energy transfer in earth changes the land
Thermal energy transfer shapes the Earth's surface through mantle convection causing geological activity and through the evaporation and precipitation cycle that alters landscapes.
Thermal energy transfer in the Earth can change the landscape in a number of ways. Here are two examples:
Convection in the Mantle: The Earth's mantle experiences convection currents due to the heat from the Earth's core and radioactive decay. These convection currents can lead to the movement of tectonic plates, resulting in geological activities such as earthquakes and volcanic eruptions that alter the land.Water Evaporation and Precipitation: Thermal energy from the sun causes evaporation of water from the Earth's surface. When this water vapor condenses, it can lead to precipitation that can contribute to soil erosion or the alteration of landscapes through the formation of rivers and valleys.In summary, the process of convection within the Earth's mantle and the evaporation and precipitation cycle are crucial for understanding how thermal energy transfer can shape the Earth's surface over time.
What is the definition of an “atom”?
Answer: The indivisible unit of matter.
Explanation:
Which of the following is a property of basic solutions but not acidic
solutions?
A. They have a slippery feel.
B. They do not conduct electricity.
C. They change the color of indicators.
D. They have a sour taste.
1.A telescope is a tool that helps people observe distant objects. In the simplest telescope design, incoming light hits a lens and is focused to a single point. This focused image is then magnified by a second lens so that it is roughly the same size as an observer's pupil. Which of the following wave behaviors plays the most important role in the functioning of this type of telescope?
Group of answer choices
reflection
resonance
refraction
interference
2.Pick the THREE statements that describe convex lenses.
Group of answer choices
They make the image of an object appear smaller.
Light rays spread out as they exit the lens.
They are thicker in the middle than at the ends
They make the image of an object appear larger.
They are thicker at the ends than in the middle.
Light rays converge as they exit the lens.
Answer:
it is refraction
Explanation:
Refraction plays the most important role in the functioning of this type of telescope. Therefore, the correct option is option C.
What is telescope?A telescope is a device that uses electromagnetic radiation to examine distant objects through their emission, absorption, or reflection. Originally referring only to an optical instrument that used lenses, reflectors, or perhaps a combination of the two to notice distant objects,
The earliest functional telescopes are refracting telescopes using glass lenses, which were created in the Netherlands in the early 17th century. They were employed for both terrestrial and astronomical purposes. Refraction plays the most important role in the functioning of this type of telescope.
Therefore, the correct option is option C.
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Liquid A has a strong IMF and Liquid B has a weak IMF. Which liquid might evaporate quicker? Explain in terms of IMFs.
Answer:
Liquid B will evaporate quicker.
Explanation:
Intermolecular forces (IMP) are the forces of attraction between molecules while intramolecular forces are force of attractions between atoms within a compound. Following are the types of intermolecular forces,
(i) Ion-Dipole Interactions
(ii) Hydrogen Bondings
(iii) Dipole-Dipole Interactions
(iv) Ion-Induced Dipole
(v) Dipole-Induced Dipole
(vi) Dispersion /London Forces
The physical properties of a compounds strongly depends upon the strength of the IMF. For example, greater the IMF greater will be the melting and boiling point. In given statement the liquid B will evaporate quicker because it has weak interaction with its neighbouring atoms hence, it has weak IMF and easily break the interaction and escape while the liquid A will not do so as it has stronger IMF.
Sort the sentences based on whether they are correct or incorrect.
Answer:
Explanation:
Correct statements:
Water boils at a temperature below 100°C at higher altitude.
Water boils at a temperature 100°C under normal pressure.
The density of water decreases on freezing.
Water expend on freezing.
False statements:
Water contract on freezing.
d. SrF2
2. Name the binary ionic compounds indicated by the following formulas:
a. AgCl
b. Zno
e. Bao
c. CaBrz
f. CaCl,
Answer: A. Silver chloride
B. Zinc oxide
C. Calcium bromide
D. Strontium fluoride
E. Barium oxide
F. Calcium chloride
Explanation:
Water temperature is general cooler where?
The temperature of water is cooler in deep oceans. The temperature there goes to 0°C to -3°C below which the water freezes. The water on the surface of the oceans and deep inside it varies because of the difference in energy of the two layers. One of the widest use of cold water is air conditioning. Cold water has a higher density than warm water. Water gets colder with profundity since chilly, salty sea water sinks to the base of the sea beds underneath the less dense hotter water close to the surface.
How many atoms would be contained in 549 grams of zinc
Answer:
5.05 × 10²⁴ Zn Atoms
Explanation:
In order to find the number of atoms we will follow these two steps;
Step 1: Finding out the moles of Zn as;
Moles = Mass / A. Mass
Moles = 549 g / 65.38 g/mol
Moles = 8.397 moles
Step 2: Calculating No. of Atoms as:
According to Avogadro's Law, each mole contains 6.022 × 10²³ particles. These particles can be any entity i.e. atoms, molecules, formula units, ions e.t.c. So,
No. of Atoms = Moles × 6.022 × 10²³ atoms/mol
No. of Atoms = 8.397 mol × 6.022 × 10²³ atoms/mol
No. of Atoms = 5.05 × 10²⁴ Zn Atoms
Are there any plans for controlling or removing zebra mussel
Answer: no
Explanation:
What is the molality of a solution made by dissolving 137.9g of sucrose in 414.1g of water?
Answer: 2.71 moles of solute for every 1 kg of solvent.
Explanation: As you know, the molality of a solution tells you the number of moles of solute present for every 1 kg of the solvent.This means that the first thing that you need to do here is to figure out how many grams of water are present in your sample. To do that, use the density of water.500.mL⋅1.00 g1mL=500. g Next, use the molar mass of the solute to determine how many moles are present in the sample.115g⋅1 mole NanO385.0g=1.353 moles NaNO3So, you know that this solution will contain 1.353moles of sodium nitrate, the solute, for 500. g of water, the solvent.In order to find the molality of the solution, you must figure out how many moles of solute would be present for 1 kg=103g of water.103g water⋅1.353 moles NaNO3500.g water=2.706 moles NaNO3You can thus say that the molality of the solution is equal to molality=2.706 mol kg−1≈2.71 mol kg−1 The answer is rounded to three sig figs.
What part of the atom takes up most of its space
Answer:
The nucleus of the atom takes up most of the space.
Explanation:
The nucleus of the atom is made up of all the protons and neutrons while the rest of it is just the electron cloud which is made up of only electrons which are so much smaller compared to the nucleus that they don't effect its mass what so ever.
What does the number above the symbol represent?
O
A. The isotope number
O
B. The atomic mass
O
C. The atomic number
O
D. The ionic number
Answer:
D. The ionic number.
Explanation:
Whenever an element losses or gains an electron; it becomes charged, thus turns to an ion. The ion can either be positively charged when it losses an electron or negarively charged when it gains an electron. The number shows the required number of electrons gained (negative) or lost (positive).
Balance the following reaction.
PA+
02 - 2P205
Answer:
P4 + 5O2 —> 2P2O5
Explanation:
A toy balloon filled with air has an internal pressure of 126.625 kPa and a volume of 2500 mL. If I take the balloon to the bottom of the ocean where the pressure is 95 atmospheres, what will the new volume of the balloon be in mL? How many moles of gas does the balloon hold? (Assume T=285K)
Using the ideal gas law, we first calculate the number of moles in the balloon using the initial conditions and then apply the combined gas law to find the new volume under increased ocean pressure. The toy balloon will have a volume of approximately 32.89 mL at the bottom of the ocean with a pressure of 95 atm and contains about 0.129 moles of gas.
Explanation:To solve for the new volume of the toy balloon at the bottom of the ocean, we will use the ideal gas law and its principle that states the product of pressure (P) and volume (V) is proportional to the number of moles (n) and the temperature (T), represented as PV = nRT, where R is the ideal gas constant. Given the internal pressure of the balloon is 126.625 kPa (which is equivalent to 1.25 atm since 1 atm = 101.325 kPa) and the volume is 2500 mL at the surface, we can calculate the number of moles of gas in the balloon using the ideal gas constant (R = 8.3145 J/mol·K or 0.0821 L·atm/mol·K for calculations involving atmospheres) and the provided temperature of 285 K.
Calculating the number of moles:
Convert the pressure to atmospheres: 126.625 kPa / 101.325 kPa/atm = 1.25 atmUse the Ideal Gas Law to find n: P1V1/T1 = nR, thus n = P1V1 / (R*T1)n = (1.25 atm * 2.5 L) / (0.0821 L·atm/mol·K * 285 K)n = 0.129 moles (approximately)Calculating the new volume at the bottom of the ocean:
Now, we apply the combined gas law to determine the new volume (V2) when the pressure is 95 atm
Using P1V1/T1 = P2V2/T2 and solving for V2 gives us V2 = P1V1T2/(P2T1)We know T2 = T1 as the temperature is constant (285 K), so V2 = P1V1/P2V2 = 1.25 atm * 2500 mL / 95 atmV2 = 32.89 mL (approximately)The new volume of the balloon at the bottom of the ocean under 95 atmospheres of pressure would be approximately 32.89 mL, and it contains about 0.129 moles of gas.
The new volume of the balloon at the bottom of the ocean is approximately 26.75 mL, and the balloon holds approximately 0.117 moles of gas.
To solve this problem, we will use Boyle's Law, which states that for a given mass of gas at constant temperature, the volume of the gas is inversely proportional to the pressure. Mathematically, this can be expressed as:
[tex]\[ P_1V_1 = P_2V_2 \][/tex]
First, we need to convert the final pressure from atmospheres to kPa to match the units of the initial pressure. We know that 1 atmosphere is approximately 101.325 kPa.
[tex]\[ P_2 = 95 \text{ atm} \times 101.325 \text{ kPa/atm} \] \[ P_2 = 9620.875 \text{ kPa} \][/tex]
Now we can use Boyle's Law to find the new volume \( V_2 \):
[tex]\[ P_1V_1 = P_2V_2 \] \[ V_2 = \frac{P_1V_1}{P_2} \] \[ V_2 = \frac{126.625 \text{ kPa} \times 2500 \text{ mL}}{9620.875 \text{ kPa}} \] \[ V_2 \approx 26.75 \text{ mL} \][/tex]
Next, to find the number of moles of gas in the balloon, we can use the ideal gas law:
[tex]\[ PV = nRT \][/tex]
We will use the initial conditions to find \( n \):
[tex]\[ n = \frac{P_1V_1}{RT} \] \[ n = \frac{126.625 \times 10^3 \text{ Pa} \times 2500 \times 10^{-6} \text{ m}^3}{8.314 \text{ J/(mol·K)} \times 285 \text{ K}} \] \[ n = \frac{126.625 \times 2.5 \text{ J}}{8.314 \times 285} \] \[ n \approx 0.117 \text{ moles} \][/tex]
Therefore, the new volume of the balloon at the bottom of the ocean is approximately 26.75 mL, and the balloon holds approximately 0.117 moles of gas."
The field at BBVA Compass Stadium is 110 yards long. Convert this to feet.
Answer:
330
Explanation:
110 times 3
The 110 yards length of the field at BBVA Compass Stadium is equivalent to 330 feet when converted using the fact that 1 yard equals 3 feet.
Explanation:The length of the field at BBVA Compass Stadium in question is 110 yards. We can convert yards to feet by using the fact that 1 yard is equivalent to 3 feet.
Therefore, multiplying 110 yards by 3 yields a result of 330 feet.
This conversion is commonly utilized because yards and feet are both units used in the US customary system of measurement, thus are commonly interchangeable depending on the context or the precision required.
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convert 1.64 pounds to grams and miligrams
Answer:
gram: 743.8915 milligram: 743891.5
Explanation:
use google my friend
1.64 pounds is equivalent to 743.904 grams or 743904 milligrams; this is achieved by using the conversion factors: 1 pound equals 0.4536 kilograms and 1 kilogram equals 1000 grams.
Explanation:To convert 1.64 pounds to grams and milligrams, we use the fact that 1 pound is equivalent to 0.4536 kilograms, and 1 kilogram is 1000 grams. Therefore, to get the weight in grams:
1.64 lb x 0.4536 kg/lb x 1000 g/kg = 743.904 g
Now, to convert grams to milligrams, we know that there are 1000 milligrams in one gram:
743.904 g x 1000 mg/g = 743904 mg
Thus, 1.64 pounds is equivalent to 743.904 grams or 743904 milligrams.
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You transfer a clear liquid from a beaker into a test tube. You heat the test tube with the unknown liquid over a Bunsen burner. The liquid begins to vaporize and after continued heating a white crystalline material is all that remains in the test tube. The test tube initially contained:
a compound
a mixture
an element
a solution
Answer:
A mixture
Explanation: I don't really have one I just know and i just can't explain it
how many moles are in 373.8 grams of bromine?
Answer:79.904
Explanation:
It's right cause it's right
Calculate molecular mass of C2H5OH
Answer:
46
Explanation:
C=12
H=1
O=16
Therefore
(12x2)+6+16= 46
Answer: 46u
Explanation:C2= (12*2)
H5= (1*5)
O= (16*1)
H= (1*1)
Molecular Mass= C2+H5+O+H
= 24+5+16+1
= 46u
Chemistry-Griffin
Emma Drummond
Percent Composition
For the following compounds, determine the formula , formula mass, and percent com
SHOW ALL WORK! Example: Sodium Chloride = NaCl
Na: 1*22.990 = 22.990
(22.990/58.443)*100 = 39.34% Na
Cl: 1*35.453 = 35.453
(35.453/58.443)*100 = 60.66% CI
Formula Mass = 58.443 g/mole
1. Hydrocyanic Acid
What is the formula for hydrocyanic acid
Answer:no
Explanation: