In a politically charged atmostphere, the D.C. City Council voted yesterday to cut the real estate tax rate on about 100,000 homes in Washington while leaving business taxes at their old level.

The cut in residential taxes, saving homeowners about $13 million, will be reflected in tax bills scheduled to be mailed Aug. 15, with the first of two installments due a month later.

The reduced tax rate on homes - $1.54 for each $100 of assessed value, a cut of $29 cents - was recommended by Mayor Walter E. Washington and council member Marion Barry (D-At Large), chairman of the council's finance and revenue committee. They are rivals in the current mayoral campaign.

Barry's attempt to win a further political dividend at yesterday's council session was deflated when he failed to win enough votes to bring up a bill that would create a jobs program for unemployed youths. Of the nine votes that were needed, he got seven.

Only minutes later, Barry himself abandoned - until after the Sept. 12 primary election - any effort to enact a reduction of income taxes on moderate-income families.

Barry, who is campaigning as "Mr. Tax Reform," introduced the employment and tax reduction bills on the eve of yesterday's meeting, and had his staff alert reporters that he had done so.

During yesterday's session, Barry lost one vote on a politically sensitive tax issue to David A. Clarke (D-Ward 1) and was upbraided by Willie J. Hardy (D-Ward 7), who used some of the sharpest words ever heard in the council chamber in accusing him of campaigning from the council dais.

Hardy, a supporter of Council Chairman Sterling Tucker for mayor, flew into a rage when Barry commented thatshe did not understand a then-pending bill that would let some hard-pressed homeowners defer part of their increased taxes until they sell their homes.

"I resent very much loose, stupid statements." Hardy told Barry, her voice rising to a shout. "I don't need to sit here and be told I don't understand. Since you're campaigning, I suggest you campaign somewhere else and not here, at my expense."

Barry did not reply. The bill, one of several tax measures enacted yesterday under Barry's sponsorship, was approved, all of them on an emergency basis, which means that they will go into effect just as soon as they are signed into a law by the mayor.

One bill created, for the first time, a dual tax structure, with residential property to be taxed at a lower rate than commercial property.

It also increased the homeowner's exemption on each dwelling - whether owner-occupied or rented - from $6,000 to $9,000, reducing the valuation used for calculating tax bills.

It also expanded the "circuit breaker" program to cover homeowners and renters with incomes up to $20,000, raising thelevel from the present $7,000. Under this program, taxpayers receive an income tax credit, based on a sliding scale, when their housing costs reach a set proportion of their income. For some taxpayers, the benefit can reach hundreds of dollars.

Separate legislation was needed to set the actual tax rates - $1.54 per $100 of assessed value for homes, $1.83 per $100 for commercial property, including apartment buildings. All property last year was taxed at $1.83.

The gap between the $1.54 rate and the $1.83 rate in 18 percent. Barry sought in the bill to limit the gap in future years to 20 percent, meeting one objection to the dual tax program voiced at a recent hearing by spokesman for business and real estate interests.

Clarke, who in 1975 introduced the first bill that would have created a dual tax rate, objected to the provision, saying it could prevent the council from raising business taxes next year.

Clarke's motion to drop the 20 percent provision was approved, 6 to 4, with Barry supported by Democrats Polly Shackleton, John A. Wilson and Arrington Dixon.

The council also approved a bill, proposed by D.C. Auditor Matthew S. Watson and sponsored by Barry to require a set proportion of rental cars to be registered in the District and to charge an 8 percent sales tax on the rental. This will yield an estimated $400,000 a year in new tax revenue.

Watson had found that most locally rented cars are registered in the suburbs.

Watson had found that most locally rented cars are registered in the suburbs.

Barry was blocked on a procedural vote when he made an inpassioned plea to bring up his newly announced program to expand jobs for unemployed youths.

He sought to spend $28.5 million next year, from the city's anticipated rise in tax revenues, to provide summer jobs next year for 15,375 youths and 1,000 jobs for school dropouts starting this fall. He said the jobless rate among youth, officially more than 40 percent, is a growing crisis.

For the matter to be brought up yesterday, the council would have had to declare an emergency. Hardy protested, saying it is "a big joke . . . to think we are going to create jobs."

Wilson also voice doubts. Tucker said he had doubts the money would be available after the city needs are met.

Although the resolution to create an emergency received a plurality in favor. 7 to 4, it faled since nine votes were needed.

Supporting Barry were Democarts Wilhelmina J. Rolark, William R. Moore and Statehood Party member Hilda Mason. Opposing were Shackleton, Tucker, Wilson and Hardy.