Answer:
50/400 × 100/1
0.125 × 100
= 12.5%
Which of the following choices is NOT evidence for the recent changes in global climate?
O prairies giving way to deserts in Africa and the American West
more and longer heat waves
O a single, normal weather event like a hurricane
O coral reefs dying off
Answer: single, normal weather event like a hurricane
Explanation:
Climate change is variation in the average weather conditions. This brings about a wetter, drier or warmer condition. Climate change is typically caused by human activities.
Some of the recent changes in global climate include prairies giving way to deserts in Africa and the American West, more and longer heat waves and coral reefs dying off.
It should be noted that a single, normal weather event like a hurricane isn't a result of climate change.
80.0 mL of oxygen gas was collected when the temperature was
20.0°C. How many milliliters will the oxygen occupy if the
temperature changes to 54.0°C?
A. 1200 mL
B. 216 mL
C. 71.7 ml
D. 89.3 mL
(Please show your work)
Answer:
89.3 mL
Explanation:
First we convert 20.0 °C and 54.0 °C to K:
20.0 °C + 273.16 = 293.16 K54.0 °C + 273.16 = 327.16 KWith the absolute temperatures we can solve this problem by using Charles' law:
T₁V₂=T₂V₁Where in this case:
T₁ = 293.16 KV₂ = ?T₂ = 327.16 KV₁ = 80.0 mLWe input the data:
293.16 K * V₂ = 327.16 K * 80.0 mLAnd solve for V₂:
V₂ = 89.3 mLWhat volume of a 1.08M KI solution would contain 0.642 moles of KI?
Answer: Volume is 0.594 litres
Explanation: Amount of moles = volume · concentration
n = Vc and V = n/c = 0.642 mol / 1.08 mol/l = 0,59344.. l
which of the following amino acids may be considered hydrophobic at physiological ph?
a. isoleucine
b. Arginine
c. Aspartic acid
d. Threonine
Answer:
Aspartic acid may be considered hydrophobic at physiological.
A sample of a food label is shown below.
Example: Cereal Box
Calories per serving - 167
Total fat - 3 grams
Total saturated fat - 1 gram
Cholesterol - 0mg
Sodium - 250mg
Total carbs - 32 grams
Dietary fiber - 4 grams
Sugars - 11 grams
Protein - 3 grams
Servings per container 5
(a) Is the Calories per serving correctly written? Show your calculation.
(b) Calculate the percent from carbohydrates per serving.
(c) Calculate the Calories if you eat one box of the cereal.
Answer:
A) It's correctly written
B) 77%
C) 835 calories
Explanation:
A) From online sources, we have number of calories as follows;
Fats: 9 calories per gram
Protein; 4 calories per gram
Carbs; 4 calories per gram
Total calories for each;
Total fat = 3 × 9 = 27 calories
Total protein = 3 × 4 = 12 calories
Total carbs = 32 × 4 = 128 calories
(sugar and dietary Fibre are classified as carbohydrates and so total carbs takes care of their calories).
Thus, total number of calories per serving = 27 + 12 + 128 = 167 calories per serving which is same as what is given.
B) percent from carbohydrates per serving = total calories from carbs/total number of calories per serving × 100% = 128/167 × 100% ≈ 77%
C) One box contains 5 servings. Thus total number of calories per box = 167 × 5 = 835 calories
What weather causes an anticyclone?
Answer:
In summer, anticyclones bring dry, hot weather. In winter, clear skies may bring cold nights and frost. In cold conditions, anticyclones may also bring fog and mist. This is because the cold forces moisture in the air to condense at low altitudes.
Answer:
an anticyclone is an area of high pressure that brings fine setteled weather. in an anticyclone the air is decending which means it is trapped on the ground and cannot rise, therefore we don't get rain!
Explanation:
13. Which of the following is NOT characteristic of metals?
how many grams of CO2 will be produced from 39 grams of C3H8 and 11 grams of O2
Answer:
Equation: C3H8 + 5O2 = 3CO2 + 4H2O (already balanced)
a) If you start with 14.8 g of C3H8 and 3.44 g of O2, determine the limiting reagant
b) Determine the number of moles of carbon dioxide produced
c) Determine the number of grams of H2O produced
d) Determine the number of grams of excess reagant left
An unknown solution has a pH of 6.8. Which of these chemicals is likely to increase the pH the most when added to the solution? (5 points)
a
NaOH
b
HCl
c
NH3
d
HNO3
Answer:
NaOH
Explanation:
An unknown solution has a pH of 6.8. The chemical that will increase the pH is NaOH. The correct option is a.
What are acid and bases?
Acids have lower pH, and they are sour and bases have high pH, and they are bitter in taste.
HCl, NH3, HNO3 are all acids and acid decrease the pH. Only NaOH is a base, and it will increase the pH.
Thus, the correct option is a. NaOH.
Learn more about acid and bases
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A compound is made by carbon, hydrogena and nitrogen and 1 g of this compound contains 91.5 mg of hydrogen and 424 mg of nitrogen. What is the molecular formula given that the molar mass is about 65 g/mol? (write the formula with elements in this sequence HNO)
Answer:
C₄H₃N
Explanation:
To solve this question we must find the moles of each atom in order to find the empirical formula (Simplest ratio of atoms present in a molecule). With empirical formula and the molar mass of the compound we can find the molecular formula as follows:
Moles H:
91.5mg H * (1mmol / 1mg) =
91.5mmol H
Moles N:
424mg N * (1mmol / 14mg) =
30.286mmol N
The ratio of moles regard to moles N (The lower number of moles is:
H = 91.5mmolH / 30.286mmolN = 3.0
N = 30.286mmolN / 30.286mmolN = 1
empirical formula = CₓH₃N
The molar mass of this formula is:
12*x + 1*3 + 1*14 = 17g/mol
Solving for X:
12X + 17g/mol = 65g/mol
12X = 48g/mol
X = 4
There are 4 atoms of carbon and molecular formula is:
C₄H₃NHow many moles of silver chloride, produced from 100 g of silver nitrate reacting with barium chloride BaCl2?
Answer:
Equation of Reaction
2AgNO3 + BaCl2 === 2AgCl + Ba(NO3)2
Molar Mass of AgNO3 = 170g/mol
Moles of reacting AgNO3 = 100g/170gmol-¹
=0.588moles of AgNO3
From the equation of reaction...2moles of AgNO3 reacts to Produce 2Moles of Silver Chloride
So Their ratio is 2:2.
This means that 0.588Moles of AgCl Will be produced too.
ANSWER...0.588MOLES OF AgCl WILL BE PRODUCED.
when aluminium and chlorine compared , which has smaller atomic size ? Why ?
aluminium has bigger atomic size than chlorine
because atomic radii decreases across the period and increases down the group
this law would hold owing to the fact that chlorine and aluminum are on the same period
An organic compound has the molecular formula C8H16O4. What is the empirical formula of the compound?
Answer:
C₂H₄O
Explanation:
Empirical formulas show the simplest ratio of atoms in a compound in whole numbers.
We can think that all the atoms are divisible by 4.
As we need the lowest number for each subscript, empirical formula is:
C₂H₄O
We have divided, 8/4 for carbon, 16/4 for H and 4/4 for O.
The empirical formula is also known as the simplest expression to represent a chemical
influnza meaning in one word
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Answer:
Yung explain
Explanation:
Shu makou du mang sugumani hinam dilomaoan
pls help i will mark brainliest Part D
Look back at your answer to part A. So far, you haven't added anything to the flask or removed
anything from it. Also, the contents of the flask have returned to the same temperature that they
were in part A. Considering the appearance of the solution in the flask, is the solution unsaturated,
saturated, or supersaturated? Explain your reasoning.
Answer:
Hello, Im Mack. Hope you're doing well. :)
Here is my Correct, custom answer for the lab Question, (I also took the same assignment and got a 100% score)
Explanation:
The heating of the sodium acetate solution made it change from super-saturated to un-saturated. Yet now that it cooled back to room temperature Im sure it is saturated. it wasn't able to disolve the excess sodium acetate left over at room temperature and had to be heated so now that it is back to room temperature I Think it will not disolve the sodium acetate left in the solution until it is heated again.
Hope this helped you out,
Please feel free to comment for further help, and I'll reply asap.
Have a great day my friend :)
Aluminum oxide forms when 3.50 moles of aluminum is combined with
3.00 moles of oxygen. What is the excess reagent? Al + O2 - ALO3
(unbalanced) *
A - oxygen
B - aluminum
C - aluminum oxide
Explanation:
Correct option is
B
18
As reaction for the formation of Al 2
is as follows:
4Al+3O
2
→Al 2
O
this shows that 4 mol reacts to 3 mol ( 96 g) of O
2
so as 3 mol O
2
to 4 mol Al
then 0.5 mol O 2 to 3, 4
×0.5=0.66 mol of Al
as 1 mol Al = 27 g
then 0.66 mol of Al=0.66×27=17.9 g≈18 g
Hence, the correct option is B.
What is the mass of 564 liters of oxygen in kilograms?
Need help ASAP!
How many moles of sodium nitrate are in 0.25 L of 1.2 M NaNO3 solution?
Answer:
[tex]\boxed {\boxed {\sf 0.3 \ mol \ NaNO_3}}[/tex]
Explanation:
Molarity is a measure of concentration in moles per liter.
[tex]molarity= \frac{moles \ of \ solute}{liters \ of \ solution}[/tex]
The molarity of the solution is 1.2 M NaNO₃ or 1.2 moles NaNO₃ per liter. There are 0.25 liters of the solution. The moles of solute are unknown, so we can use x.
molarity= 1.2 mol NaNO₃/L liters of solution=0.25 L moles of solute =x[tex]1.2 \ mol \ NaNO_3/L= \frac{x}{0.25 \ L}[/tex]
We are solving for x, so we must isolate the variable, x. It is being divided by 0.25 liters. The inverse of division is multiplication, so we multiply both sides by 0.25 L.
[tex]0.25 \ L *1.2 \ mol \ NaNO_3/L=\frac{x}{0.25 \ L} *0.25 \ L[/tex]
[tex]0.25 \ L *1.2 \ mol \ NaNO_3/L=x[/tex]
The units of liters cancel, so we are left with the units moles of sodium nitrate.
[tex]0.25 *1.2 \ mol \ NaNO_3=x[/tex]
[tex]0.3 \ mol \ NaNO_3=x[/tex]
There are 0.3 moles of sodium nitrate.
How many grams of NiNi are formed from 55.3 g of Ni2O3?
2Ni2O3(s)⟶4Ni(s)+3O2(g)
Answer:
39.2 g
Explanation:
2Ni₂O₃(s) ⟶ 4Ni(s) + 3O₂(g)
First we convert 55.3 g of Ni₂O₃ into moles, using its molar mass:
55.3 g ÷ 165.39 g/mol = 0.334 mol Ni₂O₃
Then we convert 0.334 Ni₂O₃ moles into Ni moles, using the stoichiometric coefficients of the balanced reaction:
0.334 mol Ni₂O₃ * [tex]\frac{4molNi}{2molNi_2O_3}[/tex] = 0.668 mol Ni
Finally we convert 0.668 Ni moles into grams, using its molar mass:
0.668 mol * 58.69 g/mol = 39.2 g
is this correct yes or no?
Answer:
I believe so. If I get this wrong I'm sorry.
Explanation:
Use the diagram above to answer the question. Each of the containers shown above holds a 1L volume. Which container has the
greatest number of gas molecules? Assume all containers are at the
same temperature. *
(Look at the picture)
А
B
С
D
(Explain why is this the correct answer)
Option A is correct.
This is because atoms get compressed when the pressure increases and takes less space, on the other hand, the atoms get expanded when pressure decreases and hence take more space.
Please help I need the answer now!!!
Answer:
The answer is A: (more below)
Liquid A: Neutral
Liquid B: Acid
Liquid C: Base
Explanation:
Ph scale: 1 - 6 are acids, 7 is neutral, 8 - 14 are bases.
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Learning Task 2: Give the missing number in the equation below.
1.6+ = 5 + 6
2. (9×_)×4=×(2×4)
3.(1 x 4) x 0 = x (_x 0 )
4. 17 + = 19 + 17
5. (13+6)+7=13+(+)
pasagutan po thank s
Answer:
The answers are in the explanation.
Explanation:
1. Commutative property: The order of the numbers does not affect the result:
6 + 5 = 5 + 6
2. Associative property: In add or multiply, you can operate regardless of how the numbers are grouped.
(9×2)×4=9×(2×4)
3. Associative property:
(1 x 4) x 0 = 1 x (4x 0 )
4. Commutative property:
17 + 19 = 19 + 17
5. Associative property:
(13+6)+7=13+(6+7)
The specific heat of copper is about 0.400 yg C. How much heat is needed to change the temperature of a 30.0-gram sample of copper from
20.0°C to 50.0°
A. 240 j
B. 480 j
C. 720 j
D. 1000 j
Someone please help me answer this ASAP
Answer:
Q = 360 Joules
Explanation:
specific heat of copper = 0.400 J/g° C
mass of copper = 30 g
initial temperature = 20.0°C
final temperature = 50.0°C
Using the formula:
Q = mcΔT
where;
Q = Heat Energy
[tex]Q = m*c * (T_2-T_1)[/tex]
Q = (30 × 0.400)(50-20)
Q = 360 Joules
Which description of groundwater is correct?
Groundwater cannot be replenished and is, therefore, a limited resource.
Groundwater cannot be replenished, but its supply is practically infinite.
Groundwater can be replenished by rainfall.
Groundwater can be replenished through reactions in Earth’s core.
Help Plz Which of these which substances do you think will conduct electricity when
dissolved in water? (Select all that apply)
A.Select all that apply:
B.Lithium Bromide: LiBr
C.Dimethyl Sulfoxide: C2HOS
D.Octadecanol: C18H380
E.Potassium Chloride: KCI
Answer:
Lithium Bromide: LiBr and Potassium chloride: KCl.
Explanation:
A substance that will conduct electricity when dissolved completely in water is known as an Electrolyte.
Now, electrolytes are usually salts that ionize completely in a solution unlike non - electrolytes that do not dissociate into ions in solution.
Looking at the options, the only ones that are Salts are Lithium Bromide: LiBr and Potassium chloride: KCl.
Thus, options
Lithium Bromide: LiBr and Potassium Chloride: KCI will conduct electricity
when dissolved in water.
Electrolytes are referred to as compounds which conduct electricity when
dissolved in water. A salt is a common example of a compound which
dissolves in water to generate electricity which makes it an electrolyte.
In the options the salts present are Lithium Bromide and Potassium
Chloride which is why options B and D are the most appropriate choice.
Read more about Salts here https://brainly.com/question/13818836
Which 2 minerals are present in mafic igneous rock but not found
in felsic igneous rocks?
Answer: Mafic rocks are dominated by plagioclase and pyroxene (even if you can't see them with the naked eye) and smaller amounts of olivine. Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite). There is little or no quartz.
HOPE THIS HELPS
Mixed Practice:
For questions 6-9, you may not have to use your entire flow chart. Decide where to start and end using your flow chart.
4NH3 + 5O2 → 4NO + 6H2O
MM NH3 = 17.04 g/mol; MM O2 = 32 g/mol; MM NO = 30.01 g/mol; MM H2O = 18.02 g/mol
In the above reaction, how many moles of NO are formed if 824 g of NH3 react?
27.5 mol
3510 mol
48.4 mol
774 mol
Given
Mass of NO - 824 g
Molar mass of NO - 30.01g/mol
No of moles of NO = Given mass/Molar mass
No of moles of NO = 824/30.01= 27.45 mole
Hence 27.5 moles of NO are formed!
Bromine, a brick red liquid, has a density of 3.12 g/mL at room temperature. What is the mass of 25.6 mL of bromine?
Answer:
3.12 x 25.6 = 79.9 g