Answer:
b. 54.9%
Explanation:
An emerald gemstone has the formula Be₃Al₂Si₁₆O₁₈. We can find the mass of each element in 1 mole of Be₃Al₂Si₁₆O₁₈ by multiplying the molar mass of the element by its atomicity.
Be: 3 × 9.01 g = 27.03 g
Al: 2 × 26.98 g = 53.96 g
Si: 16 × 28.09 g = 449.4 g
O: 18 × 16.00 g = 288.0 g
Total mass = 818.4 g
The mass percentage of silicon is:
(449.4 g / 818.4 g) × 100% = 54.91%
Answer:
Explanation:
The density formula is mass over volume.
Rearrange the formula for the mass, m. Multiply both sides of the formula by v.
Mass can be found by multiplying the density and volume. The density is 0.65 grams per milliliter and the volume is 45.0 cubic centimeters.
- A cubic centimeter is equal to a milliliter.
- Therefore, 45 cubic centimeters also equals 45 milliliters.
Substitute the values into the formula.
Multiply. Note the milliliters, or mL will cancel out.
The mass of the wood is 29.25 grams.
Answer:
GG= Green Gg= Green Gg=yellow
Explanation:
Whenever there is a dominant allele it will ALWAYS show, the recessive alleles or lowercase letters show when they are paired together
Answer:
Explanation:
NaOH + HNO₃ ⟶ NaNO₃ + H₂O
There are two energy flows in this reaction.
Data:
V(base) = 100.0 mL; c(base) = 0.300 mol·L⁻¹
V(acid) = 100.0 mL; c (acid) = 0.300 mol·L⁻¹
T₁ = 35.00 °C; T₂ = 37.00 °C
Calculations:
(a) q₁
We have equimolar amounts of NaOH and HNO₃
n = 0.0300 mol
q₁ = 0.0300ΔH
(b) q₂
V = 100.0 mL + 100.0 mL = 200.0 mL
m = 200.0 g
ΔT = T₂ - T₁ = 37.00 °C – 35.00 °C = 2.00 °C
q₂ = 200.0 × 4.184 × 2.00 = 1674 J
(c) ΔH
0.0300ΔH + 1674 = 0
0.0300ΔH = -1674
ΔH = -1674/0.0300
ΔH = -55 800 J/mol
ΔH = -55.8 kJ/mol
Answer:
lighting a match or water and salt