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2. How many moles of hydrogen atoms are there in 154 mL of 0.18 M H2SO4? Write your

katrin [286]

2. 0.05544 moles of hydrogen atom are present in 154 mL 0.18 M solution of H2SO4.

3. 15.2506 heat in Joules is absorbed by 150.0 mL of pure water that is heated from 21.2°C to 45.5°C.

4. 0.75 M is the concentration of Na+ ions in 25.0 mL of 1.50 M NaOH is reacted with 25.0 mL of 1.50 M HCI

Explanation:

Number of moles of H2SO4 can be calculated by the given volume and molarity from the formula:

molarity = $\frac{number of moles}{volume of teh solution}$

number of moles = molarity × volume of the solution of H2SO4

number of moles = 0.18 × 0.154 litres

= 0.02772 moles of H2SO4.

Since 1 mole of H2SO4 contains 2 moles of hydrogen

so, 0.02772 moles of H2SO4 will have x moles

$\frac{1}{2}$ = $\frac{0.0272}{x}$

2 × 0.02772 = x

0.05544 moles of hydrogen atom are present in 154 mL 0.18 M solution of H2SO4.

3. The heat absorbed is calculated from the formula:

ΔH = cp × m × ΔT ( ΔT = change in temperature in Kelvin, m in kg, cp= specific heat of water)

putting the values in formula:

ΔH = 4.184 × 0.15 × ( 318.65-294.35)

= 4.184 × 0.15× 24.3

= 15.2506 Joules of heat is absorbed.

4. The concentration of Na+ ions

the balanced equation is

NaOH + HCl⇒ NaCl + H20

from one mole of NaCl 1 mole of NaCl i.e one 1 mole of Na+ ions is formed.

number of moles of NaOH is calculated by the formula:

Molarity = $\frac{number of moles}{volume of the solution}$

number of moles = 0.025L × 1.50M

= 0.0375 moles of NaOH

so 1 mole of NaOH produces 1 mole of Na= ions

hence, 0.0375 moles produces x moles of Na+ ions

$\frac{1}{1}$ = $\frac{0.0375}{x}$

moles of Na+ is produced.

concentration of NaOH in 50 ml solution because NaOH and HCl of 25 ml reacted.

applying the molarity formula from above

Molarity = $\frac{0.0375}{0.05}$

= 0.75 M

6 0

3 years ago

Do plants uptake phosphorus as P?

salantis [7]

In general, roots absorb phosphorus in the form of orthophosphate, but can also absorb certain forms of organic phosphorus. Phosphorus moves to the root surface through diffusion.

3 0

3 years ago

A polymer sample combines five different molecular-weight fractions, each of equal weight. The molecular weights of these fracti

kakasveta [241]

Answer:

Mn = 43,783

Mw = 60,000

Mz = 73,333

narrow distribution = 1.37

Explanation:

The molecular weights of these fractions increase from 20,000 to 100,000 in increments of 20,000. This means their Mi is respectively: (The molar weight (Mi) of the fractions)

Fraction 1 : Mi = 20 *10^3

Fraction 2: Mi = 40 *10^3

Fraction 3 : Mi = 60 *10^3

Fraction 4: Mi = 80 *10^3

Fraction 5 : Mi = 100 *10^3

The ΣMi = 300*10^-3

The Wi (mass of the fractions is for all the fractions the same, let's say 1)

So Wi = 1+1+1+1+1 = 5

Since number of moles = mass / Molar mass

The number of moles is respectively: ni = Wi/Mi (x10^5)

Fraction 1 : ni = Wi/Mi = 1/20000 = 5

Fraction 2: ni = 1/40000 = 2.5

Fraction 3 : ni =1/60000 = 1.67

Fraction 4: ni = 1/80000 = 1.25

Fraction 5 : ni= 1/100000 = 1

The Σni = 11.42

Mn = ΣWi/ni = 5/11.42*10^-5 = 43,783

Mw = (ΣWi * Mi)/ΣWi = 300,000 /5 = 60,000

Mz = (ΣWi * Mi²)/ΣWi *Mi = (4*10^8 +16*10^8 +36*10^8 +64*10^8 +100*10^8) /300,000 =73,333

Mz/Mn = narrow distribution =60,000/43,783 = 1.37

7 0

3 years ago

Read 2 more answers

Proteins that allow the diffusion of ions across membranes in the direction of their concentration gradients are most likely

arlik [135]

Answer:

channel proteins

Explanation:

Channel protein allows the transport of specific substances across a cell membrane.

4 0

4 years ago

6. Write the ICE chart for the reaction of 32.0 g of sulfur and 71.0 g of chlorine: S8 + 4 Cl24S2Cl2 After completing the chart

Marianna [84]

Answer:

ICE Table Figure

a. 67.37 g $S_2Cl_2$

b. 35.62 g $Cl_2$

c. 58.61 g $S_2Cl_2$

Explanation:

For the ICE table we have to keep in mind that we have 4 moles of $Cl_2$ and 1 mol of $S_8$ and the reactives are consumed, so for $Cl_2$ we will have -4X and for $S_8$ we will have -X. Follow the same logic we will have -4X for $S_2Cl_2$ .