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
RideAnS [48]
3 years ago
15

Expressed in the correct number of significant figures the sum of 0.53 cm + 75.321 cm + 28.1 cm =

Chemistry
1 answer:
Nadya [2.5K]3 years ago
5 0

Answer:

\boxed{\text{104.0 cm}}

Explanation:

When adding or subtracting values, you must round your answer to the same "place" as the measurement with its last significant figure furthest to the left.  

That is, you round off to the same number of decimal places as the measurement with the fewest decimal places.

\begin{array}{r|l}0.5& \text{3 cm}\\+ 75.3& \text{21 cm}\\+ 28.1 & \quad\text{cm} \\= 103.9 &\text{51 cm}\\\end{array}

The measurement of 28.1 cm has one digit after the decimal point, so you round the sum to have only one digit to the right of the decimal.

However, the number to be dropped (51) is greater than 5 with only zeros or nothing following the 5.

You must round up the answer. You increase the last significant digit by one.

\text{The sum is $\boxed{\textbf{104.0 cm}}$}

You might be interested in
It has been suggested that hydrogen gas obtained by the decomposition of water might be a substitute for natural gas (principall
Aleks [24]

Answer:

Hydrogen: -141 kJ/g

Methane: -55kJ/g

The energy released per gram of hydrogen in its combustion is higher than the energy released per gram of methane in its combustion.

Explanation:

According to the law of conservation of the energy, the sum of the heat released by the combustion and the heat absorbed by the bomb calorimeter is zero.

Qc + Qb = 0

Qc = -Qb  [1]

We can calculate the heat absorbed by the bomb calorimeter using the following expression.

Q = C . ΔT

where,

C is the heat capacity

ΔT is the change in the temperature

<h3>Hydrogen</h3>

Qc = -Qb = -C . ΔT = -(11.3 kJ/°C) . (14.3°C) = -162 kJ

The heat released per gram of hydrogen is:

\frac{-162kJ}{1.15g} =-141 kJ/g

<h3>Methane</h3>

Qc = -Qb = -C . ΔT = -(11.3 kJ/°C) . (7.3°C) = -82 kJ

The heat released per gram of methane is:

\frac{-82kJ}{1.50g} =-55kJ/g

3 0
3 years ago
What is the name of CuO? Explain how you determined the bond type and the steps you used to determine the naming convention for
yulyashka [42]

The name of CuO is copper II oxide and its bond type is ionic or electrovalent bond.

<h3>What is electrovalent bond?</h3>

An ionic or electrovalent bond is the type of chemical bond where two atoms or molecules are connected to each other by electrostatic attraction.

This electrostatic attraction is as a result of the transfer of electrons from the metallic element to the non-metal.

According to this question, CuO is a chemical compound consisting of two elements namely; copper and oxygen. The compound name is copper II oxide.

Copper as a metal transfers electrons to oxygen atoms, hence, an ionic bond is formed between the molecules.

Learn more about ionic bonds at: brainly.com/question/11527546

#SPJ1

4 0
1 year ago
The reaction nacl(s) → nacl(aq) is performed in a coffee cup calorimeter, using 100 ml of h2o(l) and 5.00g of nacl. if the tempe
MrRissso [65]

Since the density of water is 1 g /mL, hence there is 100 g of H2O. So total mass is:

m = 100 g + 5 g = 105 g

 

=> The heat of reaction can be calculated using the formula:

δhrxn = m C ΔT

where m is mass, C is heap capacity and ΔT is change in temperature = negative since there is a decrease

 

δhrxn = 105 g * 4.18 J/g°C * (-2.30°C)

δhrxn = -1,009.47 J

 

=> However this is still in units of J, so calculate the number of moles of NaCl.

 

moles NaCl = 5 g / (58.44 g / mol)

moles NaCl = 0.0856 mol

 

=> So the heat of reaction per mole is:

δhrxn = -1,009.47 J / 0.0856 mol

δhrxn = -11,798.69 J/mol = -11.8 kJ/mol

5 0
3 years ago
Suppose a student started with 142.0 mg of trans-cinnamic acid, 412 mg of pyridinium tribromide, and 2.30 mL of glacial acetic a
nirvana33 [79]

Answer: Theoretical Yield = 0.2952 g

               Percentage Yield = 75.3%

Explanation:

Calculation of limiting reactant:

n-trans-cinnamic acid moles = (142mg/1000) / 148.16 = 9.584*10⁻⁴ mol

pyridium tribromide moles = (412mg/1000) / 319.82= 1.288*10⁻³ mol

  • n-trans-cinnamic acid is the limiting reactant

The molar ratio according to the equation mentioned is equals to 1:1

The brominated product moles is also = 9.584*10⁻⁴ mol

Theoretical yield = (9.584*10⁻⁴ mol) * (Mr of brominated product)

                             =  (9.584*10⁻⁴ mol) * (307.97) = 0.2952 g

Percentage Yield is : Actual Yield / Theoretical Yield = 0.2223/0.2952

                                                                                           = 75.3%

4 0
3 years ago
Why do engineers use metals in making<br> electrical wires
Montano1993 [528]

Answer:

Why is copper used for most electrical wiring? All metals have some amount of resistivity to electrical currents, which is why they require a power source to push the current through. The lower the level of resistivity, the more electrical conductivity a metal has

4 0
3 years ago
Other questions:
  • A gas of unknown molecular mass was allowed to effuse through a small opening under constant-pressure conditions. It required 10
    5·1 answer
  • You are trying to determine the volume of the balloon needed to match the density of the air in the lab. You know that if you ca
    13·1 answer
  • Which is a measure of how hot or cold something is?
    9·1 answer
  • What are the uses of an enema? Select all that apply. what are the uses of an enema? select all that apply. ?
    12·1 answer
  • 50 points please do this In your OWN WORDS DO NOT COPY FROM SOMEWHERE ELSE!
    6·1 answer
  • Which of these, all of which include earth, most likely contains the most dark matter
    9·1 answer
  • Describe the buffer capacity of the acetic acid buffer solution in relation to the addition of both concentrated and dilute acid
    5·1 answer
  • Which of the following best explains why the tundra is one of the least biologically diverse biomes
    9·1 answer
  • Find the number of cations present in 7g of sodium prosphate Na=23 g/mol O=16g/mol P=31g/mol​
    11·1 answer
  • Help me solve this question​
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!