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
egoroff_w [7]
4 years ago
15

A van moves 50 miles with a constant speed of 20 mph and another 84 miles with a constant speed of 56 mph. How much time in tota

l does it take to travel these distances?
A) 1 hour
B) 4 hours
C) 1.5 hours
D) 2.5 hours
Chemistry
1 answer:
arlik [135]4 years ago
3 0

Answer:

B) 4 hours

Explanation:

the equation relating speed , distance and time is as follows

speed = distance / time taken

the van moves 50 miles at 20 mph and the next 84 miles at 56 mph

so lets calculate the time taken at both speeds

substituting the values in the above equation

20 mph = 50 miles  / time

time taken = 50 / 20 = 2.5 hours

56 mph = 84 miles / time

time taken = 1.5 hours

the totat time taken is - 2.5 + 1.5 = 4 hours

You might be interested in
A rock which has a mass of 60 grams and a volume of 20ml whats the density
Dahasolnce [82]

Answer:0.67

Explanation:

6 0
2 years ago
When heat is applied to 80 grams of CaCO3, it yields 39 grams of CO2. Determine
galben [10]

<u>Answer:</u> The percentage yield of CO_2 is 90.26%.

<u>Explanation:</u>

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}} ......(1)

Given mass of CaCO_3 = 80 g

Molar mass of CaCO_3 = 100 g/mol

Plugging values in equation 1:

\text{Moles of }CaCO_3=\frac{80g}{100g/mol}=0.8 mol

For the given chemical equation:

CaCO_3\rightarow CaO+CO_2

By the stoichiometry of the reaction:

If 1 mole of CaCO_3 produces 1 mole of CO_2

So, 0.8 moles of CaCO_3 will produce = \frac{1}{1}\times 0.8=0.8mol of CO_2

Molar mass of CO_2 = 44 g/mol

Plugging values in equation 1:

\text{Mass of }CO_2=(0.8mol\times 44g/mol)=35.2g

The percent yield of a reaction is calculated by using an equation:

\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100 ......(2)

Given values:

Actual value of CO_2 = 35.2 g

Theoretical value of H_2CO_3 = 39 g

Plugging values in equation 2:

\% \text{yield of }CO_2=\frac{35.2g}{39g}\times 100\\\\\% \text{yield of }CO_2=90.26\%

Hence, the percentage yield of CO_2 is 90.26%.

8 0
3 years ago
A canister of acetylene has a volume of 42 l the temperature of the acetylene is 305 k and the pressure is 780 torr determined t
salantis [7]
PV = nRT

1.026atm * 42l = n * 0.0821L atm/mol K * 305K

n=1.72.

1.72 molecules.
4 0
3 years ago
What does a mole of iron weigh
r-ruslan [8.4K]

As the atomic mass of iron is 55.847u

We say that it is the mass of one mole of iron.

By formula it can be find by

No.of mole=mass in g/molar mass

Mass in gram = no.of mole x molar mass

No.of mole =1

Molar mass = 55.847g

Mass in gram = 1x55.847

= 55.847g of Fe

3 0
4 years ago
What is the mass percent of chlorine in magnesium chloride?
finlep [7]
The total mass of magnesium chloride is 95.21g/mol

The mass of chlorine is 35.45g/mol

To find the mass percent of chlorine, divide its molar mass by the total mass of the substance and multiply the result by 100:
(35.45/95.21)(100)= 37.2%
4 0
3 years ago
Other questions:
  • What planet has the highest ambient temperature?
    14·2 answers
  • Why is u-235 a good isotope of uranium for creating chain reactions?
    14·1 answer
  • How would you find out if the enthalpy for the two questions exothermic or endothermic?
    12·1 answer
  • A student collected a total of 36.04 g of water from a reaction. What number of moles of water does this represent
    12·1 answer
  • Aluminum ions react with carbonate ions to form an insoluble compound, aluminum carbonate. (a) Write the net ionic equation for
    5·1 answer
  • The specific heat of zinc is 0.39 J/g*°C. How much energy needed to change the temperature of 34g of zinc from 22°C to 57°C. Is
    9·1 answer
  • The specific gravity of gold is 19.3. What is the length of one side of a 0.4 kilograms cube of solid gold, in units of inches?
    13·2 answers
  • A gas tank contains 3 gases (N2, O2, CO2). The total pressure of the gases is 825 mmHg. If the pressure of CO2 in 125 mmHg and t
    14·1 answer
  • Circle all that apply for an anion.
    13·1 answer
  • What is the distinction between magma and lava​
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!