Three sig figs, the leading zeros are not sig figs
Answer:
25 mM Tris HCl and 0.1% w/v SDS
Explanation:
A <em>10X solution</em> is ten times more concentrated than a <em>1X solution</em>. The stock solution is generally more concentrated (10X) and for its use, a dilution is required. Thus, to prepare a buffer 1X from a 10X buffer, you have to perform a dilution in a factor of 10 (1 volume of 10X solution is taken and mixed with 9 volumes of water). In consequence, all the concentrations of the components are diluted 10 times. To calculate the final concentration of each component in the 1X solution, we simply divide the concentration into 10:
(250 mM Tris HCl)/10 = 25 mM Tris HCl
(1.92 M glycine)/10 = 0.192 M glycine
(1% w/v SDS)/10 = 0.1% w/v SDS
Therefore the final concentrations of Tris and SDS are 25 mM and 0.1% w/v, respectively.
To be able to answer this item, we assume that the given hydrogen gas is ideal such that we are able to use the Ideal Gas equation,
PV = nRT
At STP, the values of volume, pressure, and temperature are 22.4 L, 1 atm, and 273.15 K. Solving for n,
n = (1 atm x 22.4 L) / (0.0821 L.atm/mol K x 273.15 K)
n = 0.9988 mols
Each mol of hydrogen gas is 2 g.
m = (0.9988 mols) x (2 g/1 mol)
m = 1.9977 g
Density is the quotient of mass and volume,
density = 1.9977 g/ 22400 mL
density = 8.92 x 10^-5 g/mL
Bubbles and fizz are an example of a chemical reaction.
