A 2,000g of C-14 is left to decay radioactively. The half-life of Carbon-14 is approximately 5,700 years. What percentage of the sample will remain after 17,100 years?
1/8 when using usatestprep
Which statement is correct regarding the rate of the reaction below? 3A + B yields 4X + 2Y
Select the correct location on the diagram.
Ocean currents affect the climate of the landmasses they come near. Which of the following locations most likely experiences a warmer climate due to a nearby ocean current than it otherwise would? Choose the correct red circle on the diagram.
Please help thanks so much!!!
In an ecosystem, Europe is the country on map which will experience a warmer climate due to a nearby ocean current than it otherwise would.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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What is the empirical formula of a molecule containing 65.5% carbon 5.5% hydrogen and 29% oxygen?
Answer: The empirical formula is [tex]C_{3}H_{3}O_1[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of C = 65.5 g
Mass of H = 5.5 g
Mass of O = 29.0 g
Step 1 : convert given masses into moles.
Moles of C =[tex]\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{65.5g}{12g/mole}=5.5moles[/tex]
Moles of H =[tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{5.5g}{1g/mole}=5.5moles[/tex]
Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{29g}{16g/mole}=1.8moles\approx 1moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C = [tex]\frac{5.5}{1.8}=3[/tex]
For H = [tex]\frac{5.5}{1.8}=3[/tex]
For O =[tex]\frac{1.8}{1.8}=1[/tex]
The ratio of C : H : O= 3: 3: 1
Hence the empirical formula is [tex]C_{3}H_{3}O_1[/tex]
Write the balanced chemical equation for the reverse reaction. include physical states for all species.
The balanced equation for the reverse reaction would be
[tex]2SO_3 (g) < ----- > 2SO_2 (g) + O_2 (g)[/tex]
Reversible reactionsThey are reactions that proceed in opposing directions - that is, reactants to products and vice versa.
The equilibrium system between sulfur dioxide gas, oxygen gas, and sulfur trioxide gas can be represented as:
[tex]2SO_2 (g) + O_2 (g) < --- > 2SO_3 (g)[/tex]
Thus, the reverse reaction would be:
[tex]2SO_3 (g) < ----- > 2SO_2 (g) + O_2 (g)[/tex]
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The equilibrium system between sulfur dioxide gas, oxygen gas, and sulfur trioxide gas is given. Write the balanced chemical equation for the reverse reaction. Include physical states for all species.
Which of the following are true about alloy steel chains?
A.
Adapt to the shape of the load
B.
All statements are true of alloy steel chains
C.
Best choice for hoisting hot materials
D.
Must be marked with a grade or manufacture’s mark
Answer: Option (B) is the correct answer.
Explanation:
A metal that tends to combine with two or more metal elements in order to gain strength or durability etc is known as an alloy.
For example, an alloy of steel contains elements like manganese, silicon, nickel, titanium, copper etc.
Some properties of alloys of steel are as follows.
They are able to adapt to the shape of the load applied. They are the best choice for hoisting hot material.Usually they are marked with a grade or manufacture’s mark.Hence, we can conclude that all the given options are true about alloy steel chains.
Suppose your thermometer is off by 1.5 oc i.e. it reads values that are 1.5 oc higher. how would this affect the results in this experiment? (3 pts)
\Final answer:
A thermometer reading off by 1.5 °C would significantly impact the accuracy of experimental results by overestimating temperature values, potentially leading to incorrect conclusions in experiments that require precise temperature measurements.
Explanation:
If your thermometer is off by 1.5 °C, meaning it reads values that are 1.5 °C higher, this discrepancy would significantly affect the accuracy of your experimental results. This error would lead to consistently overestimated temperature readings, causing potential misinterpretations of the outcomes. For example, in experiments where precise temperature control and measurement are crucial, such as in testing product formulations or determining chemical reaction rates, an inaccurate thermometer could lead to incorrect assessments of these processes.
In laboratory settings, accurate temperature measurement is pivotal for ensuring the validity of experimental results. An error of 1.5 °C could not only impact the interpretation of a single experiment but also compound in experiments relying on precise temperature measurements to gauge reactions or behaviors, thereby misleading conclusions and potentially invalidating the experiment's purpose. Moreover, in cases like accelerated shelf life testing, a small temperature discrepancy could result in significant errors in the estimated product shelf life, underscoring the importance of using accurately calibrated equipment. Examples include estimating expiry dates based on the stability of products at increased temperatures where a minor measurement error could drastically skew the results. Hence, ensuring that laboratory equipment, especially thermometers, are correctly calibrated is essential for experimental integrity and accuracy.
Which of the following molecules is polar? CH4, Ch3OH, CO2
Use the equation. How much SiCl4 is needed to produce 2.7 moles HCl?
SiCl4 + 4 H2O --> H4SiO4 + 4 HCl
What process forms high non-volcanic mountain ranges?
A. One tectonic plate is splitting apart into two plates.
B. Two tectonic plates are colliding and pushing together.
C.One tectonic plate is sliding past another tectonic plate.
D. Two tectonic plates are colliding and one is sliding under the other.
The answer is D. Two tectonic plates are colliding and one is sliding under the other
You are at home in your air conditioned garage. You are planning a family road trip from New York to Florida. You are lnfating the tires of your suv. You fill each car-tire with about 10 Liters of air. The temperature inside your air conditioned garage is about 10 degrees Celsius. Your family packs the car, and you begin your trip to Florida. The temperature in New York is about 21 degrees Celsius, and the happen temperature in Florida is 32 degrees Celsius. Assuming the pressure stays constant from the garage all the way to Florida, what could to your car tires during your road trip.
Write a paragraph that makes a claim about what happen to the car tires
What is the mass of platinum that has 4.34x10^21 of atoms?
Identify the spectator ions in the following complete ionic equation.
2
K
+
(aq)+
S
2−
(aq)+
Pb
2+
(aq)+2
NO
−
3
(aq)→PbS(s)+2
K
+
(aq)+2
NO
−
3
(aq)
Express your answers as ions separated by a comma.
why is the solubility of khp in water greater than many fatty acids with six or more carbons?
KHP has greater water solubility than fatty acids with long hydrocarbon chains due to its polar carboxylate anion that allows for strong hydrogen bonding with water, whereas fatty acids have a hydrophilic region that becomes less significant relative to the hydrophobic chain as the chain length increases, leading to decreased solubility.
Explanation:The solubility of potassium hydrogen phthalate (KHP) in water is greater than that of fatty acids with six or more carbons mainly due to the difference in the chemical structure and polarity of the molecules. KHP possesses a highly polar functional group (carboxylate anion) that can form strong hydrogen bonds with water molecules, whereas fatty acids have long hydrocarbon chains that exhibit a hydrophobic character and tend to be less soluble in polar solvents like water. As fatty acids increase in chain length, their solubility in water decreases because the proportion of the nonpolar, hydrophobic hydrocarbon chain relative to the polar carboxyl group becomes larger, resulting in weaker interactions with water molecules.
Fatty acids with long chains, such as those with more than eight carbons, are termed amphiphilic or amphipathic. These substances have both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions, which makes them behave differently in water. For instance, fatty acids with ten or more carbon atoms are nearly insoluble in water but can form a monolayer on the water surface, displaying properties characteristic of surfactants.
The higher solubility of KHP in water compared to fatty acids with six or more carbons is due to its ionic nature and the larger proportion of hydrophobic regions in long-chain fatty acids which decrease their solubility.
The higher solubility of potassium hydrogen phthalate (KHP) in water compared to many fatty acids with six or more carbons is attributed to both its ionic nature and structural differences.
KHP is an ionic compound, meaning it dissociates into ions (potassium and hydrogen phthalate ions) in water.
These ions interact strongly with water molecules through ion-dipole interactions, facilitating its dissolution. In contrast, fatty acids remain as neutral molecules in water, lacking the strong electrostatic interactions that promote solubility.Additionally, KHP contains hydrophilic groups like the carboxylate group, which further enhance its solubility by forming hydrogen bonds with water molecules.
In contrast, the hydrophobic nature of fatty acids increases with longer carbon chains, leading to decreased solubility in water. The predominance of non-polar hydrocarbon chains in fatty acids reduces their ability to interact favorably with the polar solvent, further lowering their solubility.Therefore, the combination of KHP's ionic nature and its structural features that promote interactions with water molecules explains why it exhibits higher solubility in water compared to many fatty acids with longer carbon chains
Which law states that at constant temperature the pressure of a given amount of gas is inversely proportional to the volume of the gas?
Scientists found a fern fossil in some rock layers of the Grand Canyon. They estimated that a sample of one of the fossils originally contained 1000 carbon-14 atoms when it became 'fossilized', and at the time it was tested, it only contained 250 carbon-14 atoms. Look at the chart below. How old is the fossil?
One of the compounds used to increase the octane rating of gasoline is toluene (pictured). suppose 8.30 ml of toluene (d = 0.867 g/ml) is consumed when a sample of gasoline burns in air.
The question is about the octane rating of gasoline and compound toluene that's used as an octane enhancer. An octane rating characterizes fuel's resistance to knock, originally based on a scale with n-heptane at 0 and isooctane at 100. Replacements for toxic enhancers like tetraethyl lead now include options such as toluene and ethanol.
The question involves the concept of octane rating, which is a measure of a fuel's ability to resist knocking or pinging during combustion, used in scoring gasoline. The octane scale was established using n-heptane, with an octane rating of 0, and isooctane (2,2,4-trimethylpentane), with an octane rating of 100. Fuel blends are scored against these standards to determine their octane rating. For example, a mixture of 89% isooctane and 11% n-heptane would have an octane rating of 89, representing an intermediate grade of gasoline.
Enhancers, such as toluene or ethanol, are used to increase the octane rating of gasoline. Toluene, which has a higher octane rating than 100, provides better fuel performance than pure isooctane. Historically, tetraethyl lead was used as an anti-knock agent, but due to its toxicity, it has been phased out and replaced with other substances like MTBE and ethanol.
Consider melting ice cream. When it melts, it takes heat away from the environment and so the reaction is endothermic. When you freeze ice cream, the heat is being removed from what?
Convert the pressure 0.840 atm to mm Hg
The pressure of 0.840 atmospheres (atm) can be converted to millimeters of mercury (mm Hg) by using the conversion factor, 1 atm = 760 mm Hg. The result of this conversion is 638.4 mm Hg.
Explanation:To convert the pressure from atmospheres (atm) to millimeters of mercury (mm Hg), we use the conversion factor of 1 atm = 760 mm Hg. This is a known standard in chemistry and physics. In this case, the conversion will be as follows:
0.840 atm x 760 mm Hg/1 atm = 638.4 mm Hg
Therefore, 0.840 atm is equivalent to 638.4 mm Hg.
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Which of these is not a precaution taken at nuclear power plants to ensure safety? Safety systems are built into them. All parts are kept in good repair. Enriched uranium is the fuel source. Processes are carefully monitored.
Answer: Enriched uranium is the fuel source.
The nuclear power plants utilizes the radiation energy from the fission of the heavy molecular weight atomic particles. These radiations can cause damage when exposed to the external air, they are capable of causing explosion, mutation in the living beings. Therefore, safety measures should be taken to prevent the damages.
Enriched uranium is the fuel source is not the precaution taken at the nuclear power plant to ensure safety because it is just explaining the fact that the uranium is the source of radiation. All other factors such as safety systems are built into them, all parts are kept in good repair and processes are carefully monitored are relevant precautions.
write complete ionic and net ionic equations for, SrCO3(s)+H2SO4(aq) -> SrSO4(s) +CO2(g)+H2O(l)
2C6H5COOH + 15O2 → 14CO2 + 6H2O which of the following options gives the correct product:product ratio?
The product: product ratio in the provided chemical equation, which represents the combustion of benzene-acetic acid, is 14CO₂:6H₂O. So, for every two molecules of benzene-acetic acid reacted, 14 molecules of carbon dioxide and 6 molecules of water are produced.
Explanation:The equation provided is a chemical reaction representing the combustion of benzene-acetic acid (C₆H₅COOH). The correct product: product ratio is determined by the stoichiometric coefficients in front of each product. In this selected reaction, for every two molecules of benzene-acetic acid that react with 15 molecules of oxygen, 14 molecules of carbon dioxide (CO₂) and 6 molecules of water (H₂O) are produced.
Therefore, the product: product ratio is 14CO₂:6H₂O. This means for each reaction, you will get more than twice as much carbon dioxide as water. This ratio helps us to understand how much of each product we can expect when the reaction takes place, assuming there are sufficient reactants to complete the reaction.
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Five different substances are given to you to be dissolved in water. which substances are most likely to undergo dissolution in water? check all that apply. view available hint(s) check all that apply. benzene, c6h6 potassium iodide, ki hexane, c6h14 lithium chloride, licl sodium bromide, nabr
Which of these substances most likely dissolve in water? Check all that apply
Assuming equal concentrations, rank these solutions by pH.
Hno3(aq)+k2so3(aq)→ express your answer as a chemical equation. identify all of the phases in your answer.
Answer : The balanced chemical reaction will be,
[tex]2HNO_3(aq)+K_2SO_3(aq)\rightarrow K_2SO_4(aq)+H_2O(l)+2NO_2(g)[/tex]
Explanation :
Balanced chemical equation : It is defined as the number of atoms of individual elements present on reactant side must be equal to the product side.
When the nitric acid react with potassium sulfite to give potassium sulfate, water and nitrogen dioxide.
Thus, the balanced chemical reaction will be,
[tex]2HNO_3(aq)+K_2SO_3(aq)\rightarrow K_2SO_4(aq)+H_2O(l)+2NO_2(g)[/tex]
The balanced chemical equation is as follows:
[tex]\boxed{{\text{2HN}}{{\text{O}}_{\text{3}}}\left( {aq} \right) + {{\text{K}}_2}{\text{S}}{{\text{O}}_3}\left( {aq} \right) \to {{\text{K}}_2}{\text{S}}{{\text{O}}_4}\left( {aq} \right) + 2{\text{N}}{{\text{O}}_{\text{2}}}\left( g \right) + {{\text{H}}_{\text{2}}}{\text{O}}\left( l \right)}[/tex]
The phase of [tex]{{\mathbf{K}}_{\mathbf{2}}}{\mathbf{S}}{{\mathbf{O}}_{\mathbf{4}}}[/tex] is [tex]\boxed{{\mathbf{aqueous}}}[/tex], [tex]{\mathbf{N}}{{\mathbf{O}}_{\mathbf{2}}}[/tex] is [tex]\boxed{{\mathbf{gas}}}[/tex] and [tex]{{\mathbf{H}}_{\mathbf{2}}}{\mathbf{O}}[/tex] is [tex]\boxed{{\mathbf{liquid}}}[/tex].
Further Explanation:
The chemical reaction that contains equal number of atoms of the different elements in the reactant as well as in the product side is known as balanced chemical reaction. The chemical equation is required to be balanced to follow the Law of the conservation of mass.
The steps to balance a chemical reaction are as follows:
Step 1: Complete the reaction and write the unbalanced symbol equation.
In the given reaction, [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] reacts with [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_3}[/tex] to form [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex], [tex]{\text{N}}{{\text{O}}_{\text{2}}}[/tex] and [tex]{{\text{H}}_{\text{2}}}{\text{O}}[/tex]. The physical state of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] is aqueous, [tex]{\text{N}}{{\text{O}}_{\text{2}}}[/tex] is gas and [tex]{{\text{H}}_{\text{2}}}{\text{O}}[/tex] is liquid. The unbalanced chemical equation is as follows:
[tex]{\text{HN}}{{\text{O}}_{\text{3}}}\left( {aq} \right) + {{\text{K}}_2}{\text{S}}{{\text{O}}_3}\left( {aq} \right) \to {{\text{K}}_2}{\text{S}}{{\text{O}}_4}\left( {aq} \right) + {\text{N}}{{\text{O}}_{\text{2}}}\left( g \right) + {{\text{H}}_{\text{2}}}{\text{O}}\left( l \right)[/tex]
Step 2: Then we write the number of atoms of all the different elements that are present in a chemical reaction in the reactant side and product side separately.(Refer table in the attached image)
On the reactant side,
Number of hydrogen atoms is 1.
Number of nitrogen atoms is 1.
Number of oxygen atoms is 6.
Number of potassium atoms is 2.
Number of sulfur atoms is 1.
On the product side,Number of hydrogen atoms is 1.
Number of nitrogen atoms is 1.
Number of oxygen atoms is 6.
Number of potassium atoms is 2.
Number of sulfur atoms is 1.
Step 3: Initially, we try to balance the number of other atoms of elements except for carbon, oxygen, and hydrogen by multiplying with some number on any side. The other elements except oxygen and hydrogen are balanced.
Step 4: After this we balance the number of atoms of oxygen followed by hydrogen atoms. To balance the number of atoms of oxygen and hydrogen, we have to multiply [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] by 2, [tex]{\text{N}}{{\text{O}}_{\text{2}}}[/tex] by 2. The chemical equation is as follows:
[tex]{\text{2HN}}{{\text{O}}_{\text{3}}}\left( {aq} \right) + {{\text{K}}_2}{\text{S}}{{\text{O}}_3}\left( {aq} \right) \to {{\text{K}}_2}{\text{S}}{{\text{O}}_4}\left( {aq} \right) + 2{\text{N}}{{\text{O}}_{\text{2}}}\left( g \right) + {{\text{H}}_{\text{2}}}{\text{O}}\left( l \right)[/tex]
Step 5: Finally, we check the number of atoms of each element on both the sides. If the number is same then the chemical equation is balanced. The balanced chemical equation is as follows:
[tex]{\text{HN}}{{\text{O}}_{\text{3}}}\left( {aq} \right) + {{\text{K}}_2}{\text{S}}{{\text{O}}_3}\left( {aq} \right) \to {{\text{K}}_2}{\text{S}}{{\text{O}}_4}\left( {aq} \right) + {\text{N}}{{\text{O}}_{\text{2}}}\left( g \right) + {{\text{H}}_{\text{2}}}{\text{O}}\left( l \right)[/tex]
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Answer details:
Grade: High School
Subject: Chemistry
Chapter: Chemical reaction and equation
Keywords: Balancing, HNO3, K2SO4, K2SO3, NO2, H2O, phases, physical state, solid, liquid, gas, aqueous, law of conservation of mass.
Explain how archimedes might have used the concept of density to determine whether the king's crown was pure gold. (density of gold is known to be 19.32 g/cm3 )
Classify methanol (ch3oh) as a strong electrolyte, a weak electrolyte, or a nonelectrolyte.
Explanation:
A strong electrolyte is defined as the one which contains solute that completely dissociates into ions. Strong acids will lead to the formation of strong electrolytes.
For example, HCl will make a strong electrolyte.
Whereas a weak electrolyte is defined as the one which contains solute that slightly dissociates into ions.
For example, [tex]CH_{3}OH[/tex] is a weak electrolyte.
This is because methanol when dissolved in water does not completely dissociates into ions. Therefore, very less number of ions are present into the solution and as a result, the solution will not be able to conduct electricity.
Also, oxygen atom being more electronegative in nature will hold the hydrogen atom of O-H more tightly, Hence, very less or no hydrogen ions will not present into the solution.
Therefore, we can conclude that methanol is a weak electrolyte.
Methanol, or CH3OH, is classified as a nonelectrolyte because it does not ionize or produce ions when dissolved in water, and can't therefore conduct electricity. In contrast, substances that do dissolve in water to produce ions, and can conduct electricity are electrolytes, either strong or weak.
Explanation:The student question classifies methanol (CH3OH) as a strong electrolyte, a weak electrolyte, or a nonelectrolyte. Methanol would be classified as a nonelectrolyte.
Electrolytes are substances that when dissolved in water, they produce ions. If the process is almost 100% efficient, the substance can be considered a strong electrolyte. If only a small percentage of the substance produces ions, it is a weak electrolyte. However, substances that do not produce ions when dissolved in water are called nonelectrolytes.
Methanol, in this case, does not ionize when dissolved in water, therefore, doesn't produce ions. This classifies it as a nonelectrolyte. This can be further confirmed through a conductance test. Electrolytes can conduct electricity when dissolved in water due to the presence of ions. Since methanol doesn't produce ions when dissolved, it won't conduct electricity, substantiating its classification as a nonelectrolyte.
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Determine the total number of valence electrons in the arsenite ion, aso33−.
Final answer:
The arsenite ion (AsO₃₃⁻) has a total of 26 valence electrons, calculated by adding the valence electrons of arsenic and oxygen and then adding three more electrons to account for the ion's 3− charge.
Explanation:
To determine the total number of valence electrons in the arsenite ion (AsO₃₃⁻), we first count the valence electrons of each atom and then adjust for the charge on the ion. Arsenic (As) is in group 15 of the periodic table and has 5 valence electrons. Each oxygen (O) atom, being in group 16, has 6 valence electrons. There are three oxygen atoms, so:
Arsenic: 1 As atom × 5 valence electrons = 5 valence electronsOxygen: 3 O atoms × 6 valence electrons = 18 valence electronsAdding these together: 5 (As) + 18 (O) = 23 valence electrons. Since the arsenite ion has a 3− charge, we add three electrons to account for the negative charge. So, the total number of valence electrons for AsO₃₃⁻ is:
23 (from atoms) + 3 (from charge) = 26 valence electrons
What is the total number of valence electrons in the lewis structure of sef2o?
The total number of valence electrons in the Lewis structure of SEF2O is calculated by adding the valence electrons of each atom, giving us a total of 26 electrons.
Explanation:The total number of valence electrons in the lewis structure of SEF2O can be calculated by adding up the valence electrons in each atom. Selenium (Se) has 6 valence electrons, each Fluorine (F) has 7 (so that's 14 for 2 Fluorines), and Oxygen (O) also has 6. So, the total number of valence electrons in SEF2O is 24+2 = 26.
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The total number of valence electrons in the Lewis structure of SeF2O is 26.
Explanation:The Lewis structure of SeF2O consists of a central Se atom bonded to two F atoms and one O atom. To determine the total number of valence electrons, we need to add up the valence electrons of each particle. She has six valence electrons, each F atom has seven valence electrons, and O has six valence electrons. Therefore, the total number of valence electrons in the Lewis structure of SeF2O is 6 (Se) + 2(7) (F) + 6 (O) = 26.
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What mass of salt (nacl) should you add to 1.48 l of water in an ice cream maker to make a solution that freezes at -13.4 ∘c ? assume complete dissociation of the nacl and density of 1.00 g/ml for water?
Answer:
311.6g NaCl you should add
Explanation:
When you add a solute (NaCl) to solvent (Water), the freezing point of the solution decreases with regard to pure solvent following the equation:
ΔT = Kf × m × i
Where ΔT is change in temperature(From 0°C to -13.4°C), Kf is freezing point depression constant (1.86°C/m for water), m is molality of solution (Moles solute / 1.48 kg solvent -Because 1.48L≡1.48kg; density 1.00g/mL-) and i is Van't Hoff factor (2 for NaCl because in water, NaCl dissociates as Na⁺ and Cl⁻ ions, 2 ions).
Replacing:
13.4°C = 1.86°C/m × moles NaCl / 1.48kg × 2
5.33 = moles NaCl
As molar mass of NaCl is 58.44g/mol, mass in 5.33moles are:
5.33mol NaCl × (58.44g /mol) = 311.6g NaCl you should add