How many grams do 3.6 × 10^20 atoms of sodium weigh? Answer in units of g.

wolverine [178]

Complex meaning more complicated and detailed in difficulty

6 0

3 years ago

An environmental scientist developed a new analytical method for the determination of cadmium (cd^2+) in mussels. To validate th

Anettt [7]

Answer:

The method is accurate in the calculation of the $Cu^+2$

Explanation:

As a first step we have to calculate the average concentration of $Cu^+2$ find it by the method.

$\frac{0.782+0.762+0.825+0.838+0.761 }{5} =0.79 ppm$

Then we have to find the standard deviation:

$s=\sqrt{\frac{1}{N-1}\sum_{i=1}^N(x_i-\bar{x})^2}=0.0359$

For the confidence interval we have to use the formula:

μ=Average± $\frac{t*s}{\sqrt{n} }$

Where:

t=t student constant with 95 % of confidence and 5 data=2.78

μ= $0.79$ ± $\frac{2.78*0.0359}{\sqrt{5} }$

upper limit: 0.84

lower limit: 0.75

If we compare the limits of the value obtanied by the method (Figure 1 Red line) with the reference material (Figure 1 blue line) we can see that the values obtained by the method are within the values suggested by the reference material. So, it's method is accurate.

7 0

3 years ago

What are two possible fates of stars larger than 8 sol

attashe74 [19]

Stars born larger than 8 solar masses usually retain enough mass to undergo core collapse, with the resulting shock wave producing a Type Ib supernova (spectra without Hydrogen or Silicon lines, with Helium lines), a Type Ic supernova (without Hydrogen or Helium or Silicon lines) or a Type II supernova

I hope it’s what you need

7 0

3 years ago

How many grams of NaHCO3are in 3.75 x 10 ^-3 moles of NaHCO3 PLS HELP DUE TODAY

hodyreva [135]

Answer: m= 3.15x10-3 g NaHCO3

Explanation: To find the mass of NaHCO3 we will use the relationship between moles and molar mass. The molar mass of NaHCO3 is 84 g.

3.75x10-5 moles NaHCO3 x 84 g NaHCO3 / 1 mole NaHCO3

= 3.15x10-3 g NaHCO3

3 0

3 years ago

A sample of methane gas occupies 4.50 gallons at a temperature of 80.0 F. If the pressure is held constant, what will be the vol

Marat540 [252]

Answer:

21.19 L or 5.6 gallons

Explanation:

Data Given

initial volume V1 = 4.50 gallons

convert volume from gallons to L

1 gallon = 3.78541 L

4. 50 gallon = 3.785 L x 4.50

So,

initial volume V1 = 17.03 L

final Volume V2 = ?

initial Temperature T1 = 80° F

convert Temperature to Kelvin

T1 = ( 80° F -32) / 1.8 +273

T1 = 26.7° C + 273 = 299.7 K

final Temperature T2 = 100° C

convert Temperature to Kelvin

T2 = 100° C + 273 = 373 K

Solution:

This problem will be solved by using charles' law equation at constant pressure.

The formula used

V1 / T1 = V2 / T2

As we have to find out volume, so rearrange the above equation

V2 = V1 x T2 / T1

Put value from the data given and conversion information in above equation

V2 = 17.03 L x 373 K / 299.7 K

V2 = 21. 19 L

So the final volume of Methane gas = 21.19 L

Or for Volume in gallons

1 L = 0.26

21.19 x 0.264 = 5.6 gallons

7 0

3 years ago