Answer:
MgCl2 - 6H2O
203.3 mol
MgCl2 + 2Na = 2NaCl + Mg
22.6g
Explanation:
1. Write the formula of hydrate and find molar mass.
2. Write a balanced single replacement (don't include H2O)
3. Do the given/wanted calculation (include H2O in molar mass of given)
The correct answer is A. <span>167 milliliters of 7% solution and 333 milliliters of 4% solution and here is how:
</span><span>If x is the number of milliliters of the 7% saline solution and y is the number of milliliters of the 4% saline solution then add up to 500 milliliters total, so x + y = 500.
</span>and if we do
x + y = 500
<span>x = 500 - y </span>
<span>0.07x + 0.04y = 25 (substitute 500 - y for x) </span>
<span>0.07(500 - y) + 0.04y = 25 </span>
<span>35 - 0.07y + 0.04y = 25 </span>
<span>-0.03y + 35 = 25 </span>
<span>-0.03y = -10 </span>
<span>y = 333.333... </span>
<span>y = about 333 </span>
<span>x = 500 - y = 500 - 333 = 167
</span>Then you know why the answer is A.
Answer:
it is because of Dark Matter
Dark Matter, component of the universe whose presence is discerned from its gravitational attraction rather than its luminosity. Dark matter makes up 30.1 percent of the matter-energy composition of the universe; the rest is dark energy (69.4 percent) and “ordinary” visible matter (0.5 percent).
Dark matter is composed of particles that do not absorb, reflect, or emit light, so they cannot be detected by observing electromagnetic radiation. Dark matter is material that cannot be seen directly.
Explanation:
Hope It helps
Have A Nice Day : )
Answer: 3.05 grams
Explanation:
To find the mass in grams, we need to use Avogadro's number and the molar mass of lithium.
Avogadro's number: 6.022×10²³ atoms/mol
Molar mass: 6.94 g/mol
My Choice will be the sample C with a coefficient of absorption 62 % and the reason is that the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest. Because this sample has the highest percentage of the coefficient of absorption than the other samples, As the sound Absorption coefficient is a part of the sound energy that absorbed by a material.And Its value varies with the angles of incident and frequency. So sample C is the best to be used as a soundproof room.
