1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Aleksandr-060686 [28]
3 years ago
6

Julie's science teacher asked her to use quantitative observation to distinguish between 3 metal cylinders to identify aluminum,

brass, and copper. What should she do first?
A) Use color to identify the metals.
B) Calculate the density of the samples.
C) Determine the temperature of the metals.
D) Measure the malleability of the cylinders.
Chemistry
1 answer:
SVETLANKA909090 [29]3 years ago
8 0
Since the teacher has said to use quantitative observation, density is the easiest measurement to make. Aluminum has a density of 2.7 g/mL. Brass has a density of 8.73 g/mL. Copper has a density of 8.96 g/mL. As long as the mass and volume measurements are accurate (water displacement can be used for volume measurements), the resulting density values can be distinguished.

It may be possible to distinguish these three metals visually, based on color, but the instructions have stated to use quantitative observation.
You might be interested in
A 50/50 blend of engine coolant and water (by volume) is usually used in an automobile's engine cooling system. If a car's cooli
Diano4ka-milaya [45]

Answer:

\large \boxed{109.17 \, ^{\circ}\text{C}}

Explanation:

Data:

50/50 ethylene glycol (EG):water

V = 4.70 gal

ρ(EG) = 1.11 g/mL

ρ(water) = 0.988 g/mL

Calculations:

The formula for the boiling point elevation ΔTb is

\Delta T_{b} = iK_{b}b

i is the van’t Hoff factor —  the number of moles of particles you get from 1 mol of solute. For EG, i = 1.

1. Moles of EG

\rm n = 0.50 \times \text{4.70 gal} \times \dfrac{\text{3.785 L}}{\text{1  gal}} \times \dfrac{\text{1000 mL}}{\text{1 L}} \times \dfrac{\text{1.11 g}}{\text{1 mL}} \times \dfrac{\text{1 mol}}{\text{62.07 g}} = \text{159 mol}

2. Kilograms of water

m = 0.50 \times \text{4.70 gal} \times \dfrac{\text{3.785 L}}{\text{1  gal}} \times \dfrac{\text{998 g}}{\text{1 L}} \times \dfrac{\text{1 kg}}{\text{1000 g}} = \text{8.88 kg}

3. Molal concentration of EG

b =  \dfrac{\text{159 mol}}{\text{8.88 kg}} = \text{17.9 mol/kg}

4. Increase in boiling point

\rm \Delta T_{b} = iK_{b}b = 1 \times 0.512 \, \, ^{\circ}\text{C} \cdot kg \cdot mol^{-1} \, \times 17.9 \cdot mol \cdot kg^{-1} = 9.17 \, ^{\circ}\text{C}

5. Boiling point

\rm T_{b} = T_{b}^{\circ} + \Delta T_{b} = 100.00 \, ^{\circ}\text{C} + 9.17 \, ^{\circ}\text{C} = \mathbf{109.17 \, ^{\circ}C}\\\rm \text{The boiling point of the solution is $\large \boxed{\mathbf{109.17 \, ^{\circ}C}}$}

7 0
3 years ago
How do large storms and strong currents affect the coasts?
Nezavi [6.7K]
Its B i believe, Storms and currents can bring in sediments from other places
3 0
3 years ago
Read 2 more answers
Different microscopic organisms cause different
lozanna [386]

Answer/Explanation:

A theory has lots of scientific evidence to back it up. We know this to be true based on lots of different diseases and studies of their spread.

A hypothesis is more of a starting point - an educated guess based on limited evidence. It requires further testing before becoming a theory.

A law is something that can be generalized to lots of contexts, and is universal. Such as the law of thermodynamics.

5 0
3 years ago
A sample of seawater contains 1.3g of calcium ions in 3,100kg of solution. what is the calcium ion concentration of this solutio
MakcuM [25]
Unit ppm stands for parts per million. in terms of mass, ppm is equivalent to mg/kg.
since 1 kg is 10⁻⁶ mg, 1 kg is equivalent to million mg.
therefore mg/kg is also ppm.
there are 1.3 g of Ca ions in 3100 kg
if 3100 kg contains - 1.3 g of Ca
then 1 kg contains - 1.3 g / 3100 kg
then Ca ions - 0.42 x 10⁻³ g/kg
Ca ion concentration - 0.42 mg/kg 
therefore Ca ion concentration is 0.42 ppm
8 0
4 years ago
Help me answer this chemistry question. thank you!
tatiyna

Answer:

78.85

Explanation:

To <u>calculate the average atomic mass of the isotopes </u>we use the <em>given masses and abundances</em>, as follows:

  • Mass of Isotope 1 * Abundance of Isotope 1 + Mass of Isotope 2 * Abundance of Isotope 2 + ....

In other words:

  • 78 amu * 75/100 + 81 amu * 15/100 + 82 amu * 10/100 = 78.85

So the answer is 78.85.

8 0
3 years ago
Other questions:
  • The following data was collected when a reaction was performed experimentally in the laboratory.
    11·1 answer
  • Suppose you determined the density of a cube to be 1.40 g/cm3. would the density of the cube be different if you had a cube made
    10·1 answer
  • Properties of matter with three example each
    7·1 answer
  • In cells,____ are proteins that are needed to lower the amount of energy required to start chemical reactions.
    9·2 answers
  • How does sediment form?
    8·2 answers
  • Which statement describes an interaction between the biosphere and the atmosphere that is related to
    9·1 answer
  • 20,000 $ give a way but answer this first
    8·2 answers
  • Hello detective doge here i am kinda bored wondering if anyone has any detective work for me
    9·2 answers
  • Help me. correct answer will be marked as brnlst
    8·2 answers
  • What is a disadvantage of a series circuit?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!