Answer:
Explanation:
Density is found by dividing the mass by the volume.
The mass of the liquid is 12.7 grams.
We know that 15 mL of this liquid was added to a 50 mL graduated cylinder. Therefore, the volume is 15 mL. The 50 mL is not relevant, it only tells us about the graduated cylinder.
Substitute the values into the formula.
Divide.
Round to the nearest hundredth. The 6 in the tenth place tells us to round the 4 to a 5.
The density of the liquid is about 0.85 grams per milliliter and choice A is correct.
Equation: MgOH2 (s) --> MgO (s) + H2O (g)
And it's already balanced.
I had chemistry this semester too.
Answer:
What is the main purpose of the curiosity rover ?
Explanation:
Curiosity's mission is to determine whether the Red Planet ever was, or is, habitable to microbial life. The rover, which is about the size of a MINI Cooper, is equipped with 17 cameras and a robotic arm containing a suite of specialized laboratory-like tools and instruments.
Answer:
The first element in the periodic table is hydrogen.
Explanation:
Hydrogen has an atomic number of one, making it the first element of the periodic table. The atomic number of an element is just the number of protons in the nucleus, so hydrogen has one proton. The neutrons and electrons do not affect the atomic number. After hydrogen with one proton comes helium with two, lithium with three, beryllium with four, and so on.
From the given pH, we calculate the concentration of H+:
[H+] = 10^-pH = 10^-5.5
We then use the volume to solve for the number of moles of H+:
moles H+ = 10^-5.5M * 4.3x10^9 L = 13598 moles
From the balanced equation of the neutralization of hydrogen ion by limestone written as
CaCO3(s) + 2H+(aq) → Ca2+(aq) + H2CO3(aq)
we use the mole ratio of limestone CaCO3 and H+ from their coefficients, which is 1 mole of CaCO3 is to react with 2 moles of H+, to compute for the mass of the limestone:
mass CaCO3 = 13598mol H+(1mol CaCO3/2mol H+)
(100.0869g CaCO3/1mol CaCO3)(1kg/1000g)
= 680 kg
