How many molecules are there in 42gms of Na?

Which of the following is the best example of a "Scientific Question"?

Tju [1.3M]

Answer:

B

Explanation:

5 0

2 years ago

Lead can be prepared from galena [lead(II) sulfide] by first roasting the galena in oxygen gas to form lead(II) oxide and sulfur

Vesna [10]

Answer:

a) Step 1:

$2PbS(g)+3O_2(g)\overset{roasting}\rightarrow 2PbO(s)+2SO_2(g)$

Step 2:

$2PbO(s)+PbS(s)\overset{\Delta }\rightarrow 3Pb(l)+SO_2(g)$

b) The overall balanced reaction for given process is ;

$3PbS(s)+3O_2(g)\rightarrow 3Pb(l)+3SO_2(g)$

Explanation:

a)

Galena = $PbS$

Lead(II) oxide = $PbO$

Sulfur dioxide = $SO_2$

Step 1:

Roasting the galena in oxygen gas to form lead(II) oxide and sulfur dioxide.

Balanced equation of step 1:

$2PbS(g)+3O_2(g)\overset{roasting}\rightarrow 2PbO(s)+2SO_2(g)$ ..[1]

Step 2:

Heating the metal oxide with more galena forms the molten metal and more sulfur dioxide.

Balanced equation of step 2:

$2PbO(s)+PbS(s)\overset{\Delta }\rightarrow 3Pb(l)+SO_2(g)$ ..[2]

b)

For over all reaction add [1] and [2]. The overall balanced reaction for given process is ;

$3PbS(s)+3O_2(g)\rightarrow 3Pb(l)+3SO_2(g)$

5 0

4 years ago

Read 2 more answers

To what final concentration of NH3 must a solution be adjusted to just dissolve 0.060 mol of NiC2O4 (Ksp = 4×10−10) in 1.0 L of

ololo11 [35]

Given:
0.060 mol of NiC2O4
Ksp = 4 x 10⁻¹⁰
1.0 L of solution
Kf of Ni(NH3)6 2⁺ = 1.2 x 10⁹
NiC2O4 + 6NH3 ⇋ Ni(NH3)6 2+ + 2O4 2- 
NiC2O4 ⇋ Ni 2+ + C2O4 2- ...Ksp 
Ni2+ + 6NH3 ⇋ Ni(NH3)6 2+...Kf 

Ksp * Kf = (4 x 10⁻¹⁰) * (1.2 x 10⁹) = 0.48

K = 0.48 = [Ni(NH3)6 2+][C2O4 2-] / [NH3]⁶
0.48 = (0.060)² / [NH3]⁶ ... (dissolved C2O4 2- = 0.060M)
[NH3]⁶ = (0.060)² / 0.48 = 0.0036 / 0.48 = 0.0075
NH3 = ⁶√0.0075

NH3 = 0.44 M

3 0

3 years ago

Complete the balanced equation: Cu(NO3)2 + Na2CO3 > ?

deff fn [24]

I think its CuCO3+NaNO3 but idk if its right

7 0

3 years ago

What is the mass in grams of 1.5*10^-3 mol of sodium

Nutka1998 [239]

The Formula to find the number of moles is:
Number of Moles = Mass/ Molar Mass

Which means that Mass = Number of Moles * Molar Mass

We know that Number of Moles of Sodium Na = $1.5*10^_{-3}$ moles
If you check the Periodic Table, Molar Mass of Sodium Na = 23g/mol

So, Mass = $1.5*10^_{-3} * 23$ = $3.45 * 10^{-2}$

So, the mass in grams of $1.5*10^_{-3}$ mol of Sodium is $3.45 * 10^{-2}$

Hope this Helps :)

4 0

4 years ago

Read 2 more answers