To balance the reaction what coefficients (numbers) are needed: HBr +KOH ---> KBr + H2O

if a lead can be extrated with 92.5% efficiency,what is the mass of ore required to make a lead sphere with 750%cm radius

Lady_Fox [76]

The mass of ore required is 21 700 t.

r = 750 cm

V = $\frac{4}{3} \pi r^{3}$ = $\frac{4}{3} \pi (750 cm)^{3}$ = 1.767 × 10⁹ cm³

The density of lead is 11.34 g/cm³.

So mass of lead sphere = 1.767 × 10⁹ cm³ × $\frac{11.34 g}{1 cm^{3} }$ = 2.004 ×10¹⁰ g

2.004 ×10¹⁰ g × $\frac{1 kg}{1000 g}$ = 2.004 × 10⁷ kg

2.004 × 10⁷ kg × $\frac{1 t}{1000 kg}$ = 2.004 × 10⁴ t

92.5% efficiency means 92.5 t Pb per 100 t of ore.

Mass of ore = 2.004 × 10⁴ t Pb × $\frac{100 tore}{92.5 t Pb}$ = 2.17 × 10⁴ t ore = 21 700 t ore

6 0

2 years ago

What sample has particles with the lowest average kinetic energy

makvit [3.9K]

The sample with the lowest AVERAGE kinetic energy is
the coolest one.

The sample with the lowest TOTAL kinetic energy depends on
not only the temperature of the samples, but also on their size,
since each molecule in the sample has kinetic energy.

5 0

2 years ago

What is the composition of 'Clean dry air'<br><br> - Idk what subject its just science

Luba_88 [7]

Dry air is a mixture of nitrogen, oxygen, carbon dioxide etc.
air is a mixture of gases 78% nitrogen an 21% oxygen and other components.

7 0

2 years ago

1. Ibuprofen (C13H18O2) is the active ingredient in many nonprescription pain relievers. Each tablet contains 200 mg of ibuprofe

Dmitry_Shevchenko [17]

Answer :

The molar mass of ibuprofen is, 206.29 g/mole.

The number of moles of ibuprofen in a single tablet is, 0.000969 moles