Answer:
Mass of NaF in 250 g tube of toothpaste = 100 mg of NaF
Explanation:
Mass of fluoride per gram of toothpaste = 1 mg
From the given data, the fluoride compound that is most often used in toothpaste is sodium fluoride, NaF, which is 45% fluoride by mass, mass of sodium fluoride per gram of toothpaste can be determined as follows:
1 mg of fluoride per gram of toothpaste = 45% total mass of NaF per gram of toothpaste
100% mass of NaF in toothpaste = 100/45 * 1 mg = 2.22 mg of NaF.
Therefore, mass of NaF per gram of toothpaste is 2.22 mg.
The mass of NaF in 250 g of toothpaste is then calculated below:
In 250 g of toothpaste, mass of NaF = 250 * 2.22 mg = 99.9 mg of NaF
Why is HCI a strong acid and HCIO a weak acid?
Strong Acid: dissolves and dissociates 100% to produce protons (H+) 1. seven strong acids: HCl, HBr, HI, HNO3, H2SO4, HClO4, & HClO3 2. ... Weak Acid: dissolves but less than 100% dissociates to produce protons (H+) 1.
Which of the following explains the difference between speed and velocity?
A. Velocity has motion, and speed does not.
B. Velocity has direction, and speed does not.
C. Speed has motion, and velocity does not.
D. Speed has direction, and velocity does not.
Answer:
B. Velocity has direction, and speed does not.
Explanation:
Velocity is a vector, meaning it has both a magnitude and direction. Speed is a scalar, meaning it only has a magnitude and no direction.
Help pls!!!!!!!!!!!!!!!!!!!!!!!
Answer:
D a compound
Explanation:
A 40.5 g sample of aluminum is cooled 7.5°C. The specific heat capacity of aluminum is
0.900 J/g°C. What is the energy change for this sample?
Calculate the molality of an ethylene glycol (C2H6O2) soltuion, that has a molarity of 2.07 M. The density of the solution is 1.02 g/mL. Only enter the numerical value with 3 significant figures in the answer box below. Do NOT type in the unit (m).
Answer:
2.03
Explanation:
Let's assume we have 1 L of the solution:
There would be 2.07 ethylene glycol moles.The solution would weigh (1000 mL * 1.02 g/mL) = 1020 g.With that information we can calculate the molality:
molality = moles of solute / kg of solventmolality = 2.07 moles / (1020 ÷ 1000) = 2.03 mKeep in mind that this is only an estimate, as we used the kg of the solution and not of the solvent.
The molality of an ethylene glycol solution is 2.03 kg.
What is molality?The moles of solute divided by the mass of solvent in kilograms is known as the molality of a solution.
Calculation of molality:
Given that, molarity is 2.07 M
Density is 1.02 g/ml
Step 1: To convert the litre into grams, multiply the quantity by 1000
The weight of the solution is [tex]\bold{1.02 \;g/ml\; \times 1000 = 1020 g}[/tex]
Now, molality = moles of solute is divided by mass of solvent in kilograms.
[tex]\bold{Molality = 2.07 \times \dfrac{1020}{1000} = 2.03\; kg}[/tex]
Thus, the molality of the solution is 2.03 kg
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molality = moles of solute / kg of solvent
molality = 2.07 moles / (1020 ÷ 1000) = 2.03 m
Keep in mind that this is only an estimate, as we used the kg of the solution and not of the solvent.
The Water Cycle: Lesson
Mckenze Jelks
Which example best shows how the water cycle carries on energy transfer?
Choose the correct answer.
O a flooding river depositing silt on a floodplain
O a warm ocean current warming the air above it
O ocean water depositing sand particles on a shore
O water seeping through the soil and dissolving salts
If you eat food containing 1800 Calories per day, according to an advertisement
you will lose weight. A handbook says that a person uses 20,000 kJ per day, given normal waking and sleeping activities. Will the person lose weight if he or she eats food as suggested by the advertisement?
Answer:
No he or she will not lose weight
No, the person will not lose weight if they eat food containing 1800 Calories per day based on the given information.
To determine if a person will lose weight, we need to compare their calorie intake with their calorie expenditure. The advertisement suggests consuming 1800 Calories per day, which is equivalent to approximately 7536 kJ (1 Calorie = 4.184 kJ).
The handbook states that a person uses 20,000 kJ per day, which is their estimated calorie expenditure. If the person consumes 7536 kJ (1800 Calories) and expends 20,000 kJ per day, there is an energy imbalance. The person is consuming fewer calories than they are expending, resulting in a calorie deficit.
In this scenario, the person is likely to lose weight. To maintain their current weight, their calorie intake should match their calorie expenditure. However, since their calorie intake is lower than their expenditure, their body will need to rely on stored energy (fat reserves) to make up the difference. This can lead to weight loss over time.
It's important to note that weight loss is influenced by various factors, including individual metabolism, body composition, and overall health. Caloric intake should be balanced with proper nutrition and physical activity to support overall well-being. It's always advisable to consult a healthcare professional or registered dietitian for personalized guidance on weight management.
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Two units of distance used by scientists to describe distances in space are the light-year and astronomical unit. Why do scientists use the light-year instead of Astronomical Units to measure the distances between stars?
The speed of sound is too slow.
Telescopes can measure only in light years
Distant stars can only be seen if there is light
The smaller numbers that result from measuring with larger units are easier to use
Answer:
The smaller numbers that result from measuring with larger units are easier to use .
That’s the one, good luck!
The smaller numbers that result from measuring with larger units are easier to use.
Light year is a unit of astronomical distance that measures the distance traveled by light in one year. The distance between stars can also be measured using parsecs.
The equivalent of this distance in various units is written as follows;
1 light year (ly) = 9.5 x 10¹² km = 63,240 AU1 parsec = 3.26 lyUsing light year to represent the unit of distance is more concise because big measurement can be represented easily with small numbers using this large unit.
Thus, we can conclude that the smaller numbers that result from measuring with larger units are easier to use.
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what is 78%
of 100? help
Answer:
78
Explanation:
You have 100%, you take 22% and get 78%
How many carbon dioxide molecules should be added to the products side to obey the law of conservation of matter?
Your answer:
A.four
B.One
C.three
D.two
Answer:
four A
Explanation:
Answer: B) One
Explanation: One carbon dioxide molecule should be added to the products side to balance the equation and obey the law of conservation of matter.
Also, just took the test. One is correct.
Compare the two shampoo
Answer:
Explanation:
I think you forgot to attach an image here!
PLZZZ help asaap plzzz I give brainliest are the following reactions a SYNTHESIS, DECOMPOSITION, COMBUSTION, SINGLE REPLACEMENT or DOUBLE REPLACEMENT reactions?
N2 (g) + 3 H2 (g)→ 2NH3 (l) ______________
2 H2(g) + O2(g--> 2 H2O(g)
Answer:
Synthesis
Explanation:
Two reactants are becoming one product, so it is a synthesis reaction.
Decomposition is the opposite, so when one molecule becomes simpler atoms.
Example: 2NaCl -> Cl2 + Na
Combustion is reaction with a product of water and carbon dioxide.
Example: CH4 + 2O2 -> CO2 + 2H2O
Single displacement is when one atom takes the place of the other.
Example: K + NaCl -> KCl +Na (where K took the place of Na)
Double displacement is like single displacement but it happens twice. Think of it like the atoms exchanging partners.
Example: HCl +NaH -> NaCl + HOH
Answer:
(i) N2(g)+3H2(g) -->2NH3(g) - When the equilibrium changes, the concentrations of all substances involved in the equilibrium must also change. For our equilibrium reaction: N2(g) + 3H2(g) ⇔ 2NH3(g) + Heat
(ii) 2 H2(g) + O2(g) --> 2 H2O(g) - Synthesis Reaction
HENCE BOTH THE REACTIONS COULD BE CLASSIFIED AS SYNTHEYIC REACTION
PLEASE DO MARK MY ANSWER AS THE BRAINLIEST..
<HOPE IT HELPS>
The French Le Surete included an ex-criminal, Vidocq, who put together files describing the individual modus operendi, or the _____, of each criminal.
criminal behaviors
fingerprints
home addresses
relatives who were also criminals
Answer:criminal behavior
Explanation:
Edge 2021
Answer:
Criminal Behavior
Explanation:
12) How many moles of CO can be produced from
10.0 mol of CO2
Answer:
5
Explanation:
There are 2 moles of CO in each CO2. 10 ÷ 2 = 5
Here is the reaction of carbamic acid and ammonia to form an amide and water. There is a scheme of a reversible reaction where carbamic acid reacts with ammonia to give water and an unknown compound. Carbamic acid is H2NCOH with an oxygen atom attached to the carbon atom by a double bond. Ammonia is a nitrogen atom with three H atoms attached. Water is HOH. Draw the amide product of this reaction.
Answer:
See explanation
Explanation:
I have attempted to show the sequence of the reaction between carbamic acid and ammonia to form an amide and water and urea.
The reaction first involves the protonation of ammonia to give ammonium carbamate.
When ammonium carbamate is heated to 130-140 degrees, we obtain urea and water as the final products of the reaction
how is the massive star born
Convert 8.876 × 10^12 m^2 to units of km^2.
Answer:
[tex]8.876\times 10^{18}\ km^2[/tex]
Explanation:
In this problem, we need to convert [tex]8.876 \times 10^{12}\ m^2[/tex] to km².
We know that,
1 km = 1000 m
⇒ 1 km² = 10⁶ m²
So,
[tex]8.876 \times 10^{12}\ m^2=8.876 \times 10^{12}\times 10^6\ km^2\\\\=8.876\times 10^{18}\ km^2[/tex]
So, [tex]8.876 \times 10^{12}\ m^2[/tex] is equal to [tex]8.876\times 10^{18}\ km^2[/tex].
what are three things that are considered a chemical change
Answer:
Color change, precipitation, bubbling
Explanation:
Chemical change changes the chemical composition and undergoes a process in which it results as a new substance.
What does "X" represent in the following symbol?
80
Х
35
Answer:bromine
Explanation:
How many grams of Kr are in 2.00 mol of Kr? (4)
Answer:
1 mole is equal to 1 moles Krypton, or 83.798 grams.
Explanation:
How many moles of
salt (NaCl) is 28.7
grams?
Answer:
0.491 mol NaCl
Explanation:
Convert from grams to moles using the molar mass of NaCl:
28.7 g NaCl x 1 mol NaCl/58.44 g NaCl = 0.491 mol NaCl
The molar mass (58.44 g) can be found from adding the molar masses of the individual elements (Na and Cl); the g NaCl will cancel out (dimensional analysis), leaving you with mol NaCl.
47.4 grams of calcium carbonate (CaCO3) is dissolved in 450 mL of water. What is the molarity of this aqueous solution?
Answer:
[tex]M=1.05M[/tex]
Explanation:
Hello!
In this case, since the formula for the calculation of molarity is defined in terms of moles and volume in liters as shown below:
[tex]M=\frac{n}{V}[/tex]
Whereas the moles are computed by considering the molar mass of CaCO3 (100.09 g/mol):
[tex]n=47.4g*\frac{1mol}{100.09g}=0.4736mol[/tex]
Thus, we obtain:
[tex]M=\frac{0.4736mol}{0.450L}\\\\M=1.05M[/tex]
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THE ANSWER IS
Magnesium hydroxide (Mg(OH)2): 58.33
Iron(III) oxide (Fe2O3): 159.70
Answer:
Ok, thanks?
Have a good day
Thanks for the answer ^^...yes i only commented for the points
A sample of iron, which has a specific heat capacity of 0.449 Jg^-1℃^-1, is put into a calorimeter (see sketch at right) that contains 100.0 g of water. The iron sample starts off at container 93.3 °C and the temperature of the water starts off at 22.0 °C. When the temperature of the water stops changing it's 25.7 °C. The pressure remains constant at 1 atm.
Required:
Calculate the mass of the iron sample. Be sure your answer is rounded to 2 significant digits.
Answer:
[tex]m_{iron}=32.1g[/tex]
Explanation:
Hello!
In this case, since the interaction between hot iron and cold water allows the heat transfer from iron to water and therefore we can write up the following energetic equation:
[tex]Q_{iron}+Q_{water}=0[/tex]
Whereas the heat terms can be written in terms of mass, specific heat and temperature change:
[tex]m_{iron}C_{iron}(T_f-T_{iron}) + m_{water}C_{water}(T_f-T_{water}) = 0[/tex]
So we solve for the mass of iron as follows:
[tex]m_{iron} = \frac{m_{water}C_{water}(T_f-T_{water})}{C_{iron}(T_f-T_{iron}) }[/tex]
Now, we plug in the given data to obtain:
[tex]m_{iron} = \frac{-100g*0.449\frac{J}{g\°C} (25.7\°C-22.0\°C)}{0.449\frac{J}{g\°C} (25.7\°C-93.3\°C) }[/tex]
[tex]m_{iron}=32.1g[/tex]
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In a disproportionation reaction, the disproportionate substance
A. has exactly one oxidation state.
B. has exactly two oxidation states.
C. has at least three oxidation states.
D. has either one or two oxidation states.
Answer:
The answer is C: has at least three oxidation states.
Explanation:
you're welcome
Answer:
C
Explanation:
got it right on Edge
PLEASE HELP this is physical science.
Bone age : 22,920 years
Further explanationGiven
Nt = 2.5 g C-14
No = 40 g
half-life = 5730 years
Required
time of decay
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
t = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
Input the value :
[tex]\tt 2.5=40.\dfrac{1}{2}^{t/5730}\\\\\dfrac{2.5}{40}=\dfrac{1}{2}^{t/5730}\\\\(\dfrac{1}{2})^4=\dfrac{1}{2}^{t/5730}\\\\4=t/5730\rightarrow t=22920~years[/tex]
David went shopping with his mom for house renovations supplies. They were looking for materials that would conduct electricity. Which material should they buy?
Copper
Glass
Plastic
Wood
Answer:
this will copper this is correct answer
Question asked: David went shopping with his mom for house renovations supplies. They were looking for materials that would conduct electricity. Which material should they buy?
Answer: Copper
Explanation: Copper would be the right answer because that's the only material that would conduct electricity.
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I hope this helps!
222 g of MTBE (CO(CH3)4) are added to gasoline, resulting in a total volume of 2 L of reformulated gas (RFG). Assume that the density of RFG is 0.70 g/mL, and the density of MTBE is 0.74 g/mL. For a-d, determine the concentration of MTBE in the RFG in the following units?
a. mg/L
b. moles/L
c. % (w/w)
d. % (v/v)
e. What is the % (w/w) oxygen in the RFG due to MTBE?
Answer:
Explanation:
From the information given:
(a)
[tex]Concentration \ in \ mg/L = \dfrac{Mass \ of \ MTBE \ in \ mg}{Total \ volume (in \ L)}[/tex]
[tex]Concentration \ in \ mg/L = \dfrac{222 \times 10^3 \ mg}{22}[/tex]
[tex]Concentration \ in \ mg/L = 111 \times 10^3 \ mg/L[/tex]
(b)
[tex]number \ of \ mole s= \dfrac{mass}{molar \ mass } \\ \\ number \ of \ mole s=\dfrac{222 \ g}{88.15 \ g/mol} \\ \\ \mathbf{= 2.518 mol}[/tex]
(c)
[tex]w/w \ percentage = \dfrac{mass \ of \ MTBE }{mass \ of \ solution (RFG)}\times 100\%[/tex]
[tex]where; \\ \\ mass \ of \ (RFG) = 2L \times 0.70 g/mL \\ \\ mass \ of \ (RFG) = 2000 ml \times 0.70 g/mL \\ \\ mass \ of \ (RFG) = 1400 g[/tex]
∴
[tex]w/w \ percentage = \dfrac{222 \ g}{1400 \ g}\times 100\% = \mathbf{15.8\%}[/tex]
(d)
[tex]Volume of MTBE =\dfrac{mass \ of \ MTBE}{density \ of \ MTBE}[/tex]
[tex]Volume \ of \ MTBE = 300 \ mL\\[/tex]
∴
[tex]v/v\% = \dfrac{volume \ of \ MTBE}{volume \ of \ RFG} \\ \\ v/v\% =\dfrac{300 \ mL}{2000 \ mL}\times 100\% \\ \\ \mathbf{v/v\% = 15.00\%}[/tex]
(e)
[tex]From \the \ given \ information; \\ \\ 2.5184 \ moles\ of \ MTBE contain \ 2.5184 \ mole of oxygen[/tex]
∴
[tex]mass of oxygen MTBE = 2.5284 mol \times 16\ g/mol \\ \\ mass of oxygen MTBE = 40.3 9 \ g\\ \\ mass\ of \ RFG = 1400 g[/tex]
∴
[tex]\% w/w = \dfrac{mass \ of \ oxygen}{mass \ of RFG }=\dfrac{40.22 \ g}{1400 \ g} \times 100\%[/tex]
[tex]\% w/w == 2.88\%[/tex]
Assume That The Density Of RFG Is 0.7 G/mL And The Density Of MTBE Is ... are added to gasoline, resulting in a total volume of 2 L of reformulated gas (RFG). ... Assume that the density of RFG is 0.7 g/mL and the density of MTBE is 0.74 g/mL. Determine the concentration of MTBE in the RFG in the following units (a-d)
Natural Phenomena that cause climate change
(Need at least 2)
Answer:
1. The Earth's orbit around the Sun is an ellipse, but it does change shape. ...
The tilt in the axis of the Earth is called its obliquity
Explanation:
2.Volcanic eruptions pump out clouds of dust and ash, which block out some sunlight.
Vinegar is sold as % acidity which means a weight/volume or w/v% calculation. The density of acetic acid is 1.05 g/ml and water is (effectively) 1.0 g/ml. Recollect (from CHMY121) the %w/v refers to a solution with a certain mass of additive made up to 100 mL with the addition of (in this case) water; or gramsofsolute100mLsolution The molar mass of Acetic Acid is 60.052 g/mol. What is the molarity of CH3COOH in water of a 5% acidity vinegar solution
Answer:
0.83M is molarity of the solution
Explanation:
In a 5% w/v solution of vinegar there are 5g of acetic acid per 100mL of solution. Or 50g per liter of solution. As molarity is defined as the moles of the solute (Acetic acid) per liter of solution we need to convert the 50g per liter to moles per liter using molar mass of acetic acid:
Molarity:
50g/L * (1mol / 60.052g) = 0.8326moles/L =
0.83M is molarity of the solution