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Hydrofluoric acid reacts readily with silica in glass to produce
hexafluorosilicic acid (H2SiF6).

SiO2 (s) + 6HF (aq) H2SiF6 (aq) + 2H2O (l)

If 60 g of SiO2 and 60 g of HF react

(please answer A, B, C and D)
a. Determine the limiting reactant.

b. Determine the mass of the excess reactant.

c. Determine the Theoretical yield of H2SiF6.

d. determine the percent yield if the actual yield is 48.5 g H2SiF6.

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change?

Which set of characteristics best describes igneous rock? a) largest type of rock, made of organic matter, hardest type of rock b) least abundant type of rock, made of other rocks, made mostly of minerals c) found on all continents, contains wavy bands of stripes, contains fossils d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.