Question

Сколько молей составляют и сколько молекул (атомов) содержат: а) 128г. SO2 б) 8г. NaOH в) 49г. Na2SO4 г) 50г. CaCO3 д) 6,8г. H2S е) 280г. Fe ж) 0,9г.NO2

Answer 1

M=128(г)
n=m/M
M(SO2)=32+2*16=64(г/моль)
n=128/64=2 (моль)
N=Na*n, Na- число Авагадро = 6.02*10^23 (г/моль)
N=6.02*10^23*2=12.04*10^23(молекул)

Answer 2

Calculation of Moles and Molecules (Atoms)

Let's calculate the number of moles and molecules (atoms) for each substance given:

a) 128g of SO2: To calculate the number of moles, we can use the formula: Number of moles = Mass / Molar mass

The molar mass of SO2 is calculated as follows: Molar mass of S = 32.07 g/mol Molar mass of O = 16.00 g/mol (there are two oxygen atoms in SO2) Molar mass of SO2 = (32.07 g/mol) + 2*(16.00 g/mol) = 64.07 g/mol

Now, we can calculate the number of moles: Number of moles of SO2 = 128g / 64.07 g/mol = 2 moles

To calculate the number of molecules (atoms), we can use Avogadro's number: 1 mole of any substance contains 6.022 x 10^23 molecules (atoms).

Number of molecules (atoms) of SO2 = Number of moles of SO2 * Avogadro's number Number of molecules (atoms) of SO2 = 2 moles * 6.022 x 10^23 molecules/mol = 1.2044 x 10^24 molecules (atoms) of SO2

b) 8g of NaOH: The molar mass of NaOH is calculated as follows: Molar mass of Na = 22.99 g/mol Molar mass of O = 16.00 g/mol Molar mass of H = 1.01 g/mol Molar mass of NaOH = 22.99 g/mol + 16.00 g/mol + 1.01 g/mol = 40.00 g/mol

Now, we can calculate the number of moles: Number of moles of NaOH = 8g / 40.00 g/mol = 0.2 moles

Number of molecules (atoms) of NaOH = Number of moles of NaOH * Avogadro's number Number of molecules (atoms) of NaOH = 0.2 moles * 6.022 x 10^23 molecules/mol = 1.2044 x 10^23 molecules (atoms) of NaOH

c) 49g of Na2SO4: The molar mass of Na2SO4 is calculated as follows: Molar mass of Na = 22.99 g/mol (there are two sodium atoms in Na2SO4) Molar mass of S = 32.07 g/mol Molar mass of O = 16.00 g/mol (there are four oxygen atoms in Na2SO4) Molar mass of Na2SO4 = 2*(22.99 g/mol) + 32.07 g/mol + 4*(16.00 g/mol) = 142.04 g/mol

Now, we can calculate the number of moles: Number of moles of Na2SO4 = 49g / 142.04 g/mol = 0.345 moles

Number of molecules (atoms) of Na2SO4 = Number of moles of Na2SO4 * Avogadro's number Number of molecules (atoms) of Na2SO4 = 0.345 moles * 6.022 x 10^23 molecules/mol = 2.077 x 10^23 molecules (atoms) of Na2SO4

d) 50g of CaCO3: The molar mass of CaCO3 is calculated as follows: Molar mass of Ca = 40.08 g/mol Molar mass of C = 12.01 g/mol Molar mass of O = 16.00 g/mol (there are three oxygen atoms in CaCO3) Molar mass of CaCO3 = 40.08 g/mol + 12.01 g/mol + 3*(16.00 g/mol) = 100.09 g/mol

Now, we can calculate the number of moles: Number of moles of CaCO3 = 50g / 100.09 g/mol = 0.499 moles

Number of molecules (atoms) of CaCO3 = Number of moles of CaCO3 * Avogadro's number Number of molecules (atoms) of CaCO3 = 0.499 moles * 6.022 x 10^23 molecules/mol = 3.004 x 10^23 molecules (atoms) of CaCO3

e) 6.8g of H2S: The molar mass of H2S is calculated as follows: Molar mass of H = 1.01 g/mol (there are two hydrogen atoms in H2S) Molar mass of S = 32.07 g/mol Molar mass of H2S = 2*(1.01 g/mol) + 32.07 g/mol = 34.09 g/mol

Now, we can calculate the number of moles: Number of moles of H2S = 6.8g / 34.09 g/mol = 0.199 moles

Number of molecules (atoms) of H2S = Number of moles of H2S * Avogadro's number Number of molecules (atoms) of H2S = 0.199 moles * 6.022 x 10^23 molecules/mol = 1.198 x 10^23 molecules (atoms) of H2S

f) 280g of Fe: The molar mass of Fe is 55.85 g/mol

Now, we can calculate the number of moles: Number of moles of Fe = 280g / 55.85 g/mol = 5.01 moles

Number of molecules (atoms) of Fe = Number of moles of Fe * Avogadro's number Number of molecules (atoms) of Fe = 5.01 moles * 6.022 x 10^23 molecules/mol = 3.015 x 10^24 molecules (atoms) of Fe

g) 0.9g of NO2: The molar mass of NO2 is calculated as follows: Molar mass of N = 14.01 g/mol Molar mass of O = 16.00 g/mol (there are two oxygen atoms in NO2) Molar mass of NO2 = 14.01 g/mol + 2*(16.00 g/mol) = 46.01 g/mol

Now, we can calculate the number of moles: Number of moles of NO2 = 0.9g / 46.01 g/mol = 0.0195 moles

Number of molecules (atoms) of NO2 = Number of moles of NO2 * Avogadro's number Number of molecules (atoms) of NO2 = 0.0195 moles * 6.022 x 10^23 molecules/mol = 1.1739 x 10^22 molecules (atoms) of NO2

Summary:

a) 128g of SO2: - Number of moles: 2 moles - Number of molecules (atoms): 1.2044 x 10^24 molecules (atoms) of SO2

b) 8g of NaOH: - Number of moles: 0.2 moles - Number of molecules (atoms): 1.2044 x 10^23 molecules (atoms) of NaOH

c) 49g of Na2SO4: - Number of moles: 0.345 moles - Number of molecules (atoms): 2.077 x 10^23 molecules (atoms) of Na2SO4

d) 50g of CaCO3: - Number of moles: 0.499 moles - Number of molecules (atoms): 3.004 x 10^23 molecules (atoms) of CaCO3

e) 6.8g of H2S: - Number of moles: 0.199 moles - Number of molecules (atoms): 1.198 x 10^23 molecules (atoms) of H2S

f) 280g of Fe: - Number of moles: 5.01 moles - Number of molecules (atoms): 3.015 x 10^24 molecules (atoms) of Fe

g) 0.9g of NO2: - Number of moles: 0.0195 moles - Number of molecules (atoms): 1.1739 x 10^22 molecules (atoms) of NO2