What is the correct coefficients to balance the equation

SiO2 + HF - SiF4 + H2O

2 3 4 5

What is universal indicator? What is its advantage?

The table below describes the temperature of different colors of stars. Color Temperature red under 3,500 K orange-red 3,500 - 5,000 K white-yellow 5,000 - 6,000 K blue-white 6,000 - 7,500 K blue 7,500 - 25,000 + K If the Sun is white-yellow, which

Which one of the following represents a decrease in entropy? a) The evaporation of perfume. b) The sublimation of carbon dioxide. c) The melting of ice. d) The condensation of steam on a kitchen window.

Determine the number of atoms in 1.75 ml of mercury. (the density of mercury is 13.5 g/ml.)

Consider a 1.24 g mixture of magnesium nitrate and magnesium chloride. After dissolving this mixture in water, 0.500 M silver nitrate is added dropwise until precipitate formation is complete. The mass of the white precipitate formed is 0.419 g.

5. Identify a suitable method that would be used to separate mixture of the follow [b]Water and ethanol c]Table salt dissolved in water d] iodine and potassium Pul the table below

How much energy is needed to convert 57.3 grams of ice at 0.00°c to water at 75.0°c? specific heat (ice) = 2.10 j/g°c specific heat (water) = 4.18 j/g°c heat of fusion = 333 j/g heat of vaporization = 2258 j/g?

A certain first-order reaction (A→productsA→products) has a rate constant of 9.90*10-3 s-1s-1 at 45 ∘C∘C. How many minutes does it take for the concentration of the reactant, [A][A], to drop to 6.

Assign the oxidation number for (NH4) 3PO4

When gold is melted and formed in a mold to make a piece of jewelry, what type of change is taking place?