Round the number 3456.5 to two significant figures.

The molarity of a solution containing 7.1 g of sodium sulfate in 100 mL of an aqueous solution is

Sergio [31]

Answer:

0.5 M

Explanation:

First we have to start with the molarity equation:

$M=\frac{mol}{L}$

We need to know the amount of moles and the litters.

If we have 100 mL we can convert this value to “L”, so:

$100~mL\frac{1~L}{1000~mL}$

$0.1~ L$

Now we can continue with the moles, for this we have to know the formula of sodium sulfate $Na_2SO_4$ , with this formula we can calculate the molar mass if we know the atomic mass of each atom on the formula (Na: 23 g/mol, S: 32 g/mol, O: 16 g/mol). We have to multiply each atomic mass by the amount of atoms in the formula, so:

$molar~ mass~=~ (23*2)+(32*1)+(16*4)= ~ 142~ g/mol$

In other words:

$1~mol~ Na_2SO_4=~142~g~ of~Na_2SO_4$

Now we can calculate the moles:

$7.1~g~ of~Na_2SO_4\frac{1~mol~ Na_2SO_4}{142~g~ of~Na_2SO_4}$

$0.05~mol~ Na_2SO_4$

Finally, we can calculate the molarity:

$M=\frac{0.05~mol~ Na_2SO_4 }{0.1~ L}$

$M=0.5$

I hope it helps!

4 0

4 years ago

Read 2 more answers

A solution contains 0.182 molmol NaClNaCl and 0.897 molH2OmolH2O. Calculate the vapor pressure of the solution at 55 ∘C∘C. The v

solong [7]

Answer:

Vapor pressure of solution is 78.2 Torr

Explanation:

This is solved by vapor pressure lowering:

ΔP = P° . Xm . i

Vapor pressure of pure solvent (P°) - vapor pressure of solution = P° . Xm . i

NaCl → Na⁺ + Cl⁻ i = 2

Let's determine the Xm (mole fraction) These are the moles of solute / total moles.

Total moles = moles of solvent + moles of solute

Total moles = 0.897 mol + 0.182 mol → 1.079 mol

0.182 / 1.079 = 0.168

Now we replace on the main formula:

118.1° Torr - P' = 118.1° Torr . 0.168 . 2

P' = - (118.1° Torr . 0.168 . 2 - 118.1 Torr)

P' = 78.2 Torr

5 0

3 years ago

I WILL GIVE BRAINLIEST!!!!!

Alexxx [7]

HNO₃ + H₂S → S + NO + H₂O

Assign Oxidation Number:

L.H.S R.H.S
N in HNO₃ = +5 +2 = N in NO
S in H₂S = -2 0 = S in S

Write Half cell Reactions:
Reduction Reaction:
3e⁻ + HNO₃ → NO -------(1)
Oxidation Reaction:
H₂S → S + 2e⁻ -------(2)

Multiply eq. 1 with 2 and eq. 2 with 3 to balance electrons.

6e⁻ + 2 HNO₃ → 2 NO

3 H₂S → 3 S + 6e⁻
Cancel e⁻s,
______________________________

2 HNO₃ + 3 H₂S → 2 NO + 3 S + H₂O

Balance Oxygen Atoms by multiplying H₂O with 4, Hydrogen atoms will automatically get balance.

2 HNO₃ + 3 H₂S → 2 NO + 3 S + 4H₂O

4 0

4 years ago

In what two places minerals are form?

larisa [96]

In earths surface or the bottom of the Ocean

3 0

4 years ago

A 1.2 L weather balloon on the ground has a temperature of 25°C and is at atmospheric pressure (1.0 atm). When it rises to an el

icang [17]

Answer:

The temperature of the air at this given elevation will be 53.32425°C

Explanation:

We can calculate the final temperature through the combined gas law. Therefore we will need to know 1 ) The initial volume, 2 ) The initial temperature, 3 ) Initial Pressure, 4 ) Final Volume, 5 ) Final Pressure.

Initial Volume = 1.2 L ; Initial Temperature = 25°C = 298.15 K ; Initial pressure = 1.0 atm ; Final Volume = 1.8 L ; Final pressure = 0.73 atm

We have all the information we need. Now let us substitute into the following formula, and solve for the final temperature ( T $_2$ ),

P $_1$ V $_1$ / T $_1$ = P $_2$ V $_2$ / T $_2$ ,

T $_2$ = P $_2$ V $_2$ T $_1$ / P $_1$ V $_1$ ,

T $_2$ = 0.73 atm $*$ 1.8 L $*$ 298.15 K / 1 atm $*$ 1.2 L = ( 0.73 $*$ 1.8 $*$ 298.15 / 1 $*$ 1.2 ) K = 326.47425 K,

T $_2$ = 326.47425 K = 53.32425 C

7 0

3 years ago