Hey there!
Molar mass of nitrogen is 14.007 g.
We have 7 moles.
Multiply 7 by 14.007.
7 x 14.007 = 98.049
7 moles of nitrogen has a mass of 98.049 grams.
Hope this helps!
Answer:- The pressure of ethanol would be 109 mmHg.
Solution:- This problem is based on Clausius clapeyron equation--
Given, 
= 63.5 + 273 = 336.5 K
= 34.9 + 273 = 307.9 K
= 400 mmHg
= ?
= 39.3 kJ/mol = 39300 J/mol
R = 8.314 J/mol.K
Let's plug in the values in the equation and do the calculations.
= 1.30
On taking anti ln to both sides...
= 
= 3.67
= 400/3.67
= 109 mmHg
four covalent bonds in SiO2
To solve this problem, we use Beer's Law: A= ε.l.c
A is the absorbance- 0,558
<span>ε is</span> the molar absorptivity- is <span>15000 </span><span><span>L⋅mol-1</span><span>cm-1</span></span>
<span>l is </span>the length of the cuvette- 1 cm
<span>c is</span> the molar concentration
Applying the formula,
0,558= 15000 x 1 x c
0,558/15000= c
c= <span>3.72×<span>10⁻⁵ </span> <span>mol⋅L<span>⁻¹</span></span></span>
<span />
Matter is made up of small indivisible particles called atoms HOPE THIS HELPSSS
