Astudent needs to prepare 250 ml of a 0.900 m 0.900 m aqueous solution of sucrose, c12h22o11(aq),c12h22o11(aq), which is used frequently in biological experiments. a b c which type of glassware should be used to make this solution (assuming that the accuracy of the concentration is important)? b a c how should the correct amount of solute be obtained? measure out x cmx cm of sucrose with a ruler. measure out x molx mol of solid sucrose on a molemeter. measure out x gx g of solid sucrose on a balance. based on the selected correct unit, what is the value of x? x? x=x= how should the solute and solvent be mixed in the container? fill the continer with water to the 250 ml mark. then, add the solute. add the solute. then, fill the container to the 250 ml mark with water. mix a small amount of water with the solute to dissolve it. then, fill with water to the 250 ml mark.

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.