The reaction between calcium carbonate and hydrochloric acid can be expressed through the chemical reaction,
CaCO3 + 2HCl --> CaCl2 + H2O + CO2
The molecular weight of calcium carbonate is 100 g/mol while that of hydrochloric acid is 36.45. The equation above depicts that 100 g of calcium carbonate can be dissolved in 72.9 g of hydrochloric acid.
x = (4 g HCl)(100 g CaCO3 / 72.9 HCl)
x = 5.49 g
Answer: 5.49 g
The percent composition<span> gives you only the empirical formula.
</span><span>To get the molecular formula, you must either know the molecular mass or do an experiment to find it.</span>
Answer:
0.2 mL stock solution, 0.8 solvent, 0.1 mL first solution and 0.9 solvent
Explanation:
The final volume for fist solution is 1 mL and concentration must will be 1/5, then 1 mL/5=0.2 mL. For complete the 1 mL add the missing solvent volume 1 mL-0.2 mL=0.8 mL. For second solution, assuming final volume is 1 mL, and concentration 1/10, then we have 1 mL /10=0.1 mL solution 1/5. Completing volume, 1 mL-0.1 mL= 0.9 mL solvent.
Answer:
713 nm. It is not visible with the naked eye.
Explanation:
Step 1: Given data
- Energy of light (E): 2.79 × 10⁻¹⁹ J
- Planck's constant (h): 6.63 × 10⁻³⁴ J.s
- Speed of light (c): 3.00 × 10⁸ m/s
Step 2: Calculate the wavelength of the light
We will use the Planck-Einstein equation.
E = h × c / λ
λ = h × c / E
λ = 6.63 × 10⁻³⁴ J.s × 3.00 × 10⁸ m/s / 2.79 × 10⁻¹⁹ J
λ = 7.13 × 10⁻⁷ m
Step 3: Convert "λ" to nm
We will use the relationship 1 m = 10⁹ nm.
7.13 × 10⁻⁷ m × (10⁹ nm/1 m) = 713 nm
This light is not in the 400-700 nm interval so it is not visible with the naked eye.
