Answer:
A compound can have more than one chemical formula and still be considered the same compound.
Explanation:
Which of these are not true statements a compound?
A compound's properties are usually not the same as the properties of the elements that make it up. TRUE. For instance, the salt NaCl has different properties than the solid metal Na and the gaseous nonmetal Cl₂.
A compound always has the same composition. TRUE. The ratio of elements in a compound is constant.
A compound is made up of more than one type of atom. TRUE. Unlike elements, compounds are formed by 2 or more elements.
A compound can have more than one chemical formula and still be considered the same compound. FALSE. Each compound can have only one chemical formula.
Post Lab Questions:
1. If you need to measure the volume of a 1.0 mL sample of solution would a 100 mL
graduated cylinder be appropriate? Why or why not?
Answer:
No.
Explanation:
Graduated cylinder is an instrument in chemistry used to measure approximate volumes of liquids. But you can't make volumetric analysis with these instruments because are not accurate as enough.
In chemistry, the measure of a sample must be accurate because you work with a sample to know which sample is and which is its purity. For that reaseon, graduated cylinder in not appropriate to measure 1.0mL of a sample. You must use PIPETTES.
What volume of H2 could be produced at a temperature of 35 oC and a pressure of 769 torr by the reaction of 2.82 g of aluminum with hydrochloric acid?
Answer:
3.9 L of H2.
Explanation:
We'll begin by calculating the number of mole in 2.82 g of aluminium, Al.
This is illustrated below:
Mass of Al = 2.82 g
Molar mass of Al = 27 g/mol
Mole of Al =?
Mole = mass /Molar mass
Mole of Al = 2.82 / 27
Mole of Al = 0.104 mole
Next, we shall write the balanced equation for the reaction. This is given below:
2Al + 6HCI —> 2AlCl3 + 3H2
From the balanced equation above,
2 moles of Al reacted with 6 moles of HCl to produce 3 moles of H2.
Next, we shall determine the number of mole H2 produced by reacting 0.104 mole of Al.
This is illustrated below:
From the balanced equation above,
2 moles of Al reacted to produce 3 moles of H2.
Therefore, 0.104 mole of Al will react to produce = (0.104 x 3)/2 = 0.156 mole of H2.
Therefore, 0.156 mole of H2 was produced from the reaction.
Finally, we shall determine the volume of H2 produced by using the ideal gas equation as shown below:
Number of mole (n) of H2 = 0.156 mole
Pressure (P) = 769 torr = 769/760 = 1.01 atm
Temperature (T) = 35°C = 35°C + 273 = 308 K
Gas constant (R) = 0.0821 atm.L/Kmol
Volume (V) of H2 =?
PV = nRT
1.01 x V = 0.156 x 0.0821 x 308
Divide both side by 1.01
V = (0.156 x 0.0821 x 308) /1.01
V = 3.9 L
Therefore, 3.9 L of H2 were produced from the reaction.
A higher temperature of fresh concrete results in a __________ hydration of cement.
Answer:
more rapid
Explanation:
A higher temperature of fresh concrete results in a more rapid hydration of cement. This causes reduction in the setting time of the cement, also known as accelerated setting of the cement.
It also reduces the workability of the concrete; as it makes the movement of aggregates harder by reducing the lubricating effect of the cement.
What is the density of an object that has a volume of 26 mL and a mass of 52 g?
Answer:
Density = 2 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]
From the question
mass = 52 g
volume = 26 mL
Substitute the values into the above formula and solve for the density
That's
[tex]Density = \frac{52}{26} [/tex]
We have the final answer as
Density = 2 g/mLHope this helps you
A sample of metal has a mass of 21.17 g, and a volume of 7.98 mL. What is the density of this metal?
density:
Answer: 2.652882206 but it depends on how you round it so I would say 2.65 or 2.7 g/mL
Explanation: Density is mass divided by volume
Convert a speed of 641 cm/s641 cm/s to units of inches per minute. Also, show the unit analysis by dragging components into the unit‑factor slots.
Answer:
[tex]15141.7\frac{in}{min}[/tex]
Explanation:
Hello,
In this case, by knowing that one inch equals 2.54 centimetres and 1 minute equals 60 seconds, the required velocity in inches per minute turns out:
[tex]641\frac{cm}{s}*\frac{1in}{2.54cm}*\frac{60s}{1min}}\\\\15141.7\frac{in}{min}[/tex]
Best regards.
What intermolecular forces are present among molecules in dimethyl ether, CH3OCH3?
a) London forces only
b) hydrogen bonding only
c) both London dispersion forces and hydrogen bonding
d) both London dispersion forces and dipole-dipole forces
Answer:
London forces only
Explanation:
Dimethyl ether is a nonpolar organic compound. Remember that for nonpolar organic substances, London forces are the primary intermolecular forces present.
Since dimethyl ether is a nonpolar organic compound, then it has London forces as its major intermolecular force. Intermolecular forces hold molecules of a substance together in a given state of matter.
An aluminum plate is 78 cm wide and 35 cm long. The mass of the plate is 44,226 g. Determine its thickness. [The density of lead is 2.70g/cm^3]
Answer:
i try to solve it for you, and i aplode a similer question for you
Explanation:
Determine the pH of the following solutions, given their hydrogen ion concentration. a. [H+] = 10^-5 M
Answer:
pH = 5Explanation:
The pH of the solution can be found by using the formula
pH = - log [H+]
From the question
[H+] = 10^-5 M
Substitute the value into the above formula and solve for the pH
That's
[tex]pH = - log( {10}^{ - 5} ) [/tex]
We have the final answer as
pH = 5
Hope this helps you
100 billion in scientific notation?
Answer: 1×10^11
Explanation:
concept to know: scientific notation must be written in the form of a × 10^b
where 0<a<10.
100 billion= 100,000,000,000
there are 11 zeros after 1
1 × 10^11
Hope this helps!! :)
Please show some work For the reaction: NO(g) + 1/2 O2(g) → NO2(g) ΔH°rxn is -114.14 kJ/mol. Calculate ΔH°f of gaseous nitrogen monoxide, given that ΔH°f of NO2(g) is 33.90 kJ/mol. Answers: 181.9 kJ/mol -35.64 kJ/mol 91.04 kJ/mol 148.0 kJ/mol -114.1 kJ/mol
Answer: ΔH°f of gaseous nitrogen monoxide is 148.0 kJ/mol
Explanation:
The balanced chemical reaction is,
[tex]NO(g)+\frac{1}{2}O_2(g)\rightarrow NO_2(g)[/tex]
The expression for enthalpy change is,
[tex]\Delta H_{rxn}=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)][/tex]
[tex]\Delta H_{rxn}=[(n_{NO_2}\times \Delta H_f_{NO_2})]-[(n_{O_2}\times \Delta H_f_{O_2})+(n_{NO}\times \Delta H_f_{NO})][/tex]
where,
n = number of moles
[tex]\Delta H_{O_2}=0[/tex] (as heat of formation of substances in their standard state is zero
Now put all the given values in this expression, we get
[tex]-114.14=[(1\times 33.90)]-[(\frac{1}{2}\times 0)+(1\times \Delta H_f{NO})][/tex]
[tex]\Delta H_f{NO}=148.0kJ/mol[/tex]
Therefore, ΔH°f of gaseous nitrogen monoxide is 148.0 kJ/mol
A student has a cube that has a mass of 5.5g and a volume of 4.10 cm3. What substance does he have?
Answer:
1- d= m/v d=540/200 d=2,7 g/cm
Explanation:
Answer:
BELOW
Explanation:
[tex]Density = \frac{Mass}{Volume}\\ \\D=?\\mass = 5.5g\\volume = 4.10\\\\D = \frac{5.5}{4.10} \\\\Density = 1.34[/tex]
Fill in the blank.
5.22x10^-3 = [? ]x 10^-2
Answer:
?=0.522
Explanation:
5.22*10^-3=?*10^-2
5.22*0.01=?*0.1
0.522=?
This is my first time answer question, thx!
Answer:
0.522
Explanation:
9.44 x 10^3 In standard form
write about about who wants make lunch for himself
Answer:
Make your question clear friend
Explanation:
...
Answer:
A grown man when living single will make lunch by himself for himself
Explanation:
can anyone explain it to me, please?
Answer:
2×10² cg
Explanation:
We'll begin by converting each of the above to the same unit of measurement.
In this case, we shall convert each of the above to kg. This can be obtained as follow:
Conversion of cg to kg
1 cg = 1×10¯⁵ Kg
Therefore,
2×10² cg = 2×10² × 1×10¯⁵
2×10² cg = 0.002 kg
Conversion of dg to Kg
1 dg = 1×10¯⁴ kg
Therefore,
10 dg = 10 × 1×10¯⁴
10 dg = 0.001 kg
Conversion of mg to kg.
1 mg = 1×10¯⁶ Kg
Therefore,
2×10² mg = 2×10² × 1×10¯⁶
2×10² mg = 0.0002 kg
Conversion of ng to kg
1 ng = 1×10¯¹² kg
Therefore,
1×10⁵ ng = 1×10⁵ × 1×10¯¹²
1×10⁵ ng = 0.0000001 Kg
Summary
1. 2×10² cg = 0.002 kg
2. 10 dg = 0.001 kg
3. 2×10² mg = 0.0002 kg
4. 0.001 kg
5. 1×10⁵ ng = 0.0000001 Kg
From the above calculation, 2×10² cg is the highest mass.
What color would the cyanidin indicator turn in an acidic solution?
Answer:
it turns red in colour.
Explanation:
Consider the reaction 5P4O6 + 8I2 4P2I4 + 3P4O10. How many grams of iodine must be added to 7.15 g of P4O6 to have a 5.00 % excess of iodine?
Answer:
You must add 13.86g of I₂
Explanation:
In the reaction:
5 P₄O₆ + 8I₂ → 4P₂I₄ + 3P₄O₁₀
5 moles of P₄O₆ reacts with 8 moles of I₂.
First, we need to determine how many moles of I₂ reacts completely with 7.15g of P₄O₆ (Molar mass: 219.88g/mol, thus:
7.15g P₄O₆ * (1mol / 219.88g) = 0.0325 moles P₄O₆.
Using the chemical reaction, the moles of I₂ that reacts are:
0.0325 moles P₄O₆ * ( 8 moles I₂ / 5 moles P₄O₆) = 0.0520 moles of I₂ react completely.
As molar mass of I₂ is 253.81g/mol, the mass of I₂ that reacts completely is:
0.0520 moles of I₂ * (253.81g / mol) =
13.2g of I₂.
As you must add 5.00% of excess:
13.2g + 5%13.2g =
You must add 13.86g of I₂
Janey loves this time of year because she loves eating marshmallow Peeps. One day, she eats ten peeps; 8 of them have a mass of 100 g, 1 of them has a mass of 150 g, and 1 of them has a mass of 200 g. What is the average mass of all the People that Jany ate? Show your work.
Answer:
115g
Explanation:
100*8=800
800+150+200=1150
1150/10=115
What change would you expect on the rate of the reaction of ethanol with 2-iodo-2-methylbutane if the nucleophile concentration is halved by adding diethyl ether as an inert solvent and the alkyl halide concentration is unchanged
Answer:
The rate of reaction is unchanged
Explanation:
The rate of reaction of tertiary alkyl halides with a nucleophile is independent of the nucleopohile concentration but depends only on the initial concentration of the alkyl halide since tertiary alkyl halides reacts via SN1 mechanism.
The nucleophile concentration does not come into the rate equation for the reaction hence any change in its concentration is inconsequential in determining the overall rate of reaction, hence the rate of reaction is unchanged when the nucleophile concentration is halved.
1 mole of ribose (C5H10O5(s)) has a greater entropy than 1 mole of sucrose (C12H22O11(s)) True or false
Answer:
False
Explanation:
Hello,
In this case, it is possible to substantiate that the statement is false, since the entropy of sucrose is greater than the entropy of ribose due to the fact that molar mass of the sucrose (342 g/mol) is greater than the molar mass of ribose (150 g/mol) and the general rule states that the greater the molar mass the greater the entropy.
Best regards.
Can scientific ideas ever change?
Answer:
Yes Scientific ideas change over time as our evidence improves.
Explanation:
A scientific idea is an explanation for how something works, or the truth about some aspect of the world, that was figured out using the scientific process. ... Scientific ideas change over time as our evidence improves. The more experiments we do, and the more data we collect, the better our scientific ideas become.
Answer:
Yes scientific ideas can change...That's why they are called ideas so it may be right or wrong... ideas are just guesses that you consider may work or not.... I hope this helps you
Perform the given operation and report the answer with the appropriate number of significant figures. 4.910 km - 0.08 km = ?
Answer:
4.83 km
Explanation:
Let's consider the following subtraction.
4.910 km - 0.08 km
For an addition or a subtraction, the rule for significant figures is as follows: limit the reported answer to the rightmost column that all numbers have significant figures in common, in this case, 2 figures after the decimal point.
4.910 km - 0.08 km = 4.83 km
What is the molarity (M) of .5 liter of a solution that has 205 g of NaCl dissolved in it?
Answer:
Molarity = 7 mol / LExplanation:
Since the mass of NaCl and it's volume has been given we can find the molarity by using the formula
[tex]C = \frac{m}{M \times v} [/tex]where
C is the molarity
m is the mass
M is the molar mass
v is the volume
From the question
v = 0.5 L
m = 205 g
We must first find the molar mass and then substitute the values into the above formula
M( Na) = 23 , M( Cl) = 35.5
Molar mass of NaCl = 23 + 35.5 =
58.5 g/mol
So the molarity of NaCl is
[tex]C = \frac{205}{0.5 \times 58.5} \\ C = \frac{205}{29.25} [/tex]
C = 7.00854
We have the final answer as
Molarity = 7 mol / LHope this helps you
Acetic acid is a weak acid with a pKa of 4.76. What is the concentration of acetate in a buffer solution of 0.2M at pH 4.9. Give your answer in M but as a numeral only to 2 decimal places.
Answer:
[tex][base]=0.28M[/tex]
Explanation:
Hello,
In this case, by using the Henderson-Hasselbach equation one can compute the concentration of acetate, which acts as the base, as shown below:
[tex]pH=pKa+log(\frac{[base]}{[acid]} )\\\\\frac{[base]}{[acid]}=10^{pH-pKa}\\\\\frac{[base]}{[acid]}=10^{4.9-4.76}\\\\\frac{[base]}{[acid]}=1.38\\\\[/tex]
[tex][base]=1.38[acid]=1.38*0.20M=0.28M[/tex]
Regards.
Which of the following pure liquids is the best solvent for sodium fluoride?a. CCl4b. C2C6c. HCld. BCl3e. PCl5
Answer:
HCl
Explanation:
The best solvent for NaF is a polar liquid. The only liquid having a significant dipole moment among the options is HCl due to the large electro negativity difference between hydrogen and chlorine.
The polar solvent can interact with the NaF via its dipoles such that the NaF dissolves due to ion-dipole interaction.
Distillation is a method that depends on differences in the boiling points of liquids to separate the components of a liquid mixture. Explain why you would separate a homogeneous mixture of two miscible liquids in this way but not a mixture of two immiscible liquids.
Explanation:
for immiscible liquids it is quite easy to separate and the separating funnel can be used but for miscible liquid they form a single entity and separating them is quite impossible if the differences in temperature is not considered,so in distillation the one with lower boiling point evaporates out living behind the one with high boiling point
Consider the following reaction
2 N2 (g) + O2 (g) —-> 2 N2O (g) FinalH = + 163.2 kJ/mol
b) How much heat is required to produce 25.0 g of N2O by this reaction? Show all calculations.
Answer:
92.72 kJ
Explanation:
2 N₂ (g) + O₂ (g) —-> 2 N₂O
According to question , one mole of N₂O requires 163.2 kJ of heat
Molecular weight of N₂O = 44 gm
25 g N₂O = 25 / 44 mole
25 / 44 mole will require 163.2 x 25 / 44 kJ
= 92.72 kJ
27. The unit of volume in the metric system is the liter,
which consists of 1000 milliliters. How many liters or
milliliters is each of the following common English
system measurements approximately equivalent to?
a. a gallon of gasoline
b. a pint of milk
c. a cup of water
Liters and millilitres are the most common units of volume.
The volume equal to a gallon of gasoline is 3785 m L which is equal to 3.785 L.
The volume equal to pint of milk is 473...
A a cup of water is 0.24 L
Using what you know of map making terms and concepts and word parts, define hemisphere in your own words.
Answer:
The Earth is divided into two halves by the prime meridian, forming two half spheres divided vertically. The Earth is also divided into two halves by the equator, creating two half spheres divided horizontally.
Explanation:
I took it on edge ( :