Answer:
62.98 % of the sample of hydrate is water
Explanation:
Step 1: Data given
Mass of the sample of a hydrate of sodium carbonate (Na2CO3) = 2.026 grams
After heating, the mass of the sample is 0.750 g
Molar mass H2O = 18.02 g/mol
Step 2: Calculate mass of water
Mass water = mass of hydrate - mass of sample after heating
Mass water = 2.026 grams - 0.750 grams
Mass water = 1.276 grams
Step 3: Calculate mass % percent of water
Mass % of water = (mass of water / total mass hydrate) * 100 %
Mass % of water = (1.276 grams / 2.026 grams) *100 %
Mass % of water = 62.98 %
62.98 % of the sample of hydrate is water
Answer is: <span>fewer drops of 6 M sulfuric acid, because concentration of H</span>⁺ is greater than in hydrochloric acid with same concentration.<span>
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Chemical dissociation of hydrochloric acid in water:
HCl(aq) → H⁺(aq) + Cl⁻(aq).
Chemical dissociation of sulfuric acid in water:
H₂SO₄(aq) → 2H⁺(aq) + SO₄²⁻(aq).
From chemical reaction: c(HCl) = c(H⁺) = 6 M.
c(H⁺) = 2c(H₂SO₄) = 2 · 6 M = 12 M; concentration of hydrogen cations.
PV = nRT —> n = PV/RT
P = 2.90 atm
V = 4.80 L
R = 0.08206 L atm / mol K
T = 62.0 + 273 = 335 K (make sure you convert from celsius to kelvin)
n = (2.90 • 4.80) / (0.08206 • 335) = 0.506 moles of gas
Answer:
m = 17
Explanation:
From the question we were given that
Triangle WZY is bisected by ZX; ZW = ZY
∠YXZ = (6m – 12)°
Based on the characteristics of the triangle, we see that triangle WYZ is an isosceles triangle (that is, triangle WXZ is equal to triangle YXZ)
<YXZ = <WXZ = 90°
Using ∠YXZ = (6m – 12)°
We have:
(6m – 12)° = 90°
6m = 90 + 12 ⇒ 6m = 102
m = 102 ÷ 6 = 17
m = <u>17</u>
<u>We therefore see that m is equal to 17</u>
<span>E=hν</span> where E is the energy of a single photon, and ν is the frequency of a single photon. We recall that a photon traveling at the speed of light c and a frequency ν will have a wavelength λ given by <span>λ=<span>cν</span></span>λ will have an energy given by <span>E=<span><span>hc</span>λ</span></span><span>λ=657</span> nm. This will be <span>E=<span><span>(6.626×<span>10<span>−34</span></span>)(2.998×<span>108</span>)</span><span>(657×<span>10<span>−9</span></span>)</span></span>=3.0235×<span>10<span>−19</span></span>J</span>
So we now know the energy of one photon of wavelength 657 nm. To find out how many photons are in a laser pulse of 0.363 Joules, we simply divide the pulse energy by the photon energy or <span>N=<span><span>E<span>pulse </span></span><span>E<span>photon</span></span></span>=<span>0.363<span>3.0235×<span>10<span>−19</span></span></span></span>=1.2×<span>1018</span></span>So there would be <span>1.2×<span>1018</span></span><span> photons of wavelength 657 nm in a pulse of laser light of energy 0.363 Joules.</span>