Answer:
D) SrCO3(s) + 2 HNO2(aq) → Sr(NO2)2 + H2O + CO2(g)
Explanation:
When an acid react with carbonate, it produces nitrate, carbon-dioxide gas and water molecule. When nitrous acid react with Strontium carbonate, three products are formed i. e. Strontium nitrate, carbon-dioxide gas and water. In the reaction, both nitrous acid and Strontium carbonate exchange their partners with each other and forming a different products.
1.
V = 200 mL (volume)
c = 3 M = 3 mol/L (concentration)
First we convert mL to L:
200 mL = 0.2 L
Then we calculate the moles using the formula: n = V × c = 0.2 L × 3 mol = 0.6 mol
Finally, we just use the molar mass of CaF2 to calculate the actual mass:
molar mass = 78 g/mol
The formula is: m = n × mm (mass = moles × molar mass)
m = 0.6 mol × 78 g/mol = 46.8 g
2.
For this question the steps are exactly like the first question.
V = 50mL = 0.05 L
c = 12 M = 12 mol/L
n = V × c = 0.05 L × 12 mol/L = 0.6 mol
molar mass (HCl) = 36.5 g/mol
m = n × mm = 0.6 mol × 36.5 g/mol = 21.9 g.
3.
The steps for this question are the opposite way.
m(K2CO3) = 250 g
molar mass = 138 g/mol
n = m ÷ mm = 1.81 mol
c = 2 mol/L
V = n ÷ c = 1.81 mol ÷ 2 mol/L = 0.905 L = 905 mL
They exist in the outer orbitals
Answer:
B. accepted value x 0.1
Explanation:
in the equation provided
Maximum allowed value of percentage error = 10%
put this value in the equation in stead of percentage error we get,
so maximum error = .1 x accepted value
10 % percentage error means the experimental value has 10 % error compared to accepted value.so error will be 10 % of the accepted value
or .1 times of accepted value
A factor that is changed in an experiment is called the Independent Variable.
