All categories

4 years ago

Determine the number of significant figures for each. a) 65.74 b) 60.009 c) 66_ d) 65.750

Chemistry

1 answer:

Anastasy [175]4 years ago

4 0

Answer:

a) 65.74 = 4 significant figures

b) 60.009 = 5 significant figures

c) 66_ = 2 significant figures

d) 65.750 = 5 significant figures

Explanation:

Significant figures or digits is defined as the total number of digits in a number that have meaning and contribute to the precision of the given number.

a) 65.74 = 4 significant figures, all the non-zero figures are considered significant.

b) 60.009 = 5 significant figures, zeros present between non-zero figures are significant.

c) 66_ = 2 significant figures, all the non-zero figures are considered significant.

d) 65.750 = 5 significant figures, all the non-zero figures and the trailing zero after the decimal are significant.

You might be interested in

If 1.20 moles of an ideal gas occupy a volume of 18.2 l at a pressure of 1.80 atm, what is the temperature of the gas, in degree

scoundrel [369]

We can calculate for temperature by assuming the equation for ideal gas law:

P V = n R T

Where,

P = pressure = 1.80 atm

V = volume = 18.2 L

n = number of moles = 1.20 moles

R = gas constant = 0.08205746 L atm / mol K

Substituting to the given equation:

T = P V / n R

T = (1.8 atm * 18.2 L) / (1.2 moles * 0.08205746 L atm / mol K)

T = 332.70 K

We can convert K unit to ˚C unit by subtracting 273.15 to Kelvin, therefore

T = 59.55 ˚<span>C</span>

6 0

3 years ago

A sample weighing 3.110 g is a mixture of Fe 2 O 3 (molar mass = 159.69 g/mol) and Al 2 O 3 (molar mass = 101.96 g/mol). When he

grandymaker [24]

Answer:

The mass fraction of ferric oxide in the original sample : $\frac{723}{3110}$

Explanation:

Mass of the mixture = 3.110 g

Mass of $Fe_2O_3=x$

Mass of $Al_2O_3=y$

After heating the mixture it allowed to react with hydrogen gas in which all the ferric oxide reacted to form metallic iron and water vapors where as aluminum oxide did not react.

$Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(g)$

Mass of mixture left after all the ferric oxide has reacted = 2.387 g

Mass of mixture left after all the ferric oxide has reacted = y

$x=3.110 g- y=3.110 g - 2.387 g = 0.723 g$

The mass fraction of ferric oxide in the original sample :

$\frac{0.723 g}{3.110 g}=\frac{723}{3110}$

5 0

3 years ago

Who taught us how planets move?

alexdok [17]

Answer:

It is <u>KEPLER</u>

Explanation:

Kepler defined the sun's orbit.

okay.

6 0

3 years ago

naturally occurring bromine molecules, br2 have masses of 158, 160, and 162. they occur in the relative abundances 25.69%, 49.99

4vir4ik [10]

The average atomic mass of an element can be determined by multiplying the individual masses of the isotopes with their respective relative abundances, and adding them.

Average atomic mass of Br = 158 amu(0.2569) + 160 amu(0.4999) + 162 amu(0.2431)
Average atomic mass = 159.96 amu

As described in the problem, the relative abundance for Br-79 is 25.69%. This is because 2 atoms of Br is equal to 79*2 = 158 amu. Similarly, the relative abundance of Br-81 is 81*2 = 162, which is 24.31%.

4 0

3 years ago

What is bed rock made of

Darya [45]

Answer:

Bedrock is the hard, solid rock beneath surface materials such as soil and gravel.

Bedrock can be made of most types of rock, such as granite, limestone, or sandstone.

Hope this helps!

8 0

3 years ago

Read 2 more answers